• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1999.06a
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• pp.195-200
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• 1999

In computer graphics, the modeling and simulation of flames is a challenging problem. In this paper, we propose an approach for the simulation of a fire disaster. We use particle systems to describe the dynamic behavior fire. The illumination of dynamic flame is rendered by progressive radiosity algorithm.

• 한국전산유체공학회:학술대회논문집
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• 2009.11a
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• pp.1-1
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• 2009

In this presentation, I talk about various fluid simulation methods that have been developed for computer graphics special effects since 1996. They are all based on CFD but sacrifice physical reality for visual plausability and time. But as the speed of computer increases rapidly and the capability of GPU (graphics processing unit) improves, methods for more physical realism have been tried. In this talk, I will focus on four aspects of fluid simulation methods for computer graphics: (1) particle level-set methods, (2) particle-based simulation, (3) methods for exact satisfaction of incompressibility constraint, and (4) GPU-based simulation. (1) Particle level-set methods evolve the surface of fluid by means of the zero-level set and a band of massless marker particles on both sides of it. The evolution of the zero-level set captures the surface in an approximate manner and the evolution of marker particles captures the fine details of the surface, and the zero-level set is modified based on the particle positions in each step of evolution. (2) Recently the particle-based Lagrangian approach to fluid simulation gains some popularity, because it automatically respects mass conservation and the difficulty of tracking the surface geometry has been somewhat addressed. (3) Until recently fluid simulation algorithm was dominated by approximate fractional step methods. They split the Navier-Stoke equation into two, so that the first one solves the equation without considering the incompressibility constraint and the second finds the pressure which satisfies the constraint. In this approach, the first step introduces error inevitably, producing numerical diffusion in solution. But recently exact fractional step methods without error have been developed by fluid mechanics scholars), and another method was introduced which satisfies the incompressibility constraint by formulating fluid in terms of vorticity field rather than velocity field (by computer graphics scholars). (4) Finally, I want to mention GPU implementation of fluid simulation, which takes advantage of the fact that discrete fluid equations can be solved in parallel.

• Smart Media Journal
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• v.4 no.2
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• pp.9-16
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• 2015

Fluids appear in innumerable phenomena; therefore, it is interesting to reproduce those phenomena by computer graphics techniques. However, this process is not trivial. We work with a fluid simulation that uses Navier-Stokes equations to model the fluid, a semi-Lagrangian approach to solve it and the level set method to track the surface of the fluid. Modified versions of the Navier-Stokes equations for computer graphics allow us to create a wide diversity of effects. In this paper, we propose a technique that allows us to integrate a force inspired by surface tension into the model. We describe which information we need and how to modify the model with this new approach. We end up with a modified simulation that has additional effects that might be suitable for computer graphics purposes. The effects that we are able to recreate are small waves and droplet-like formations close to the surface of the fluid. This model preserves the overall behavior governed by the Navier-Stokes equations.

• Proceedings of the Korea Society for Simulation Conference
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• 2001.10a
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• pp.237-247
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• 2001

In this paper we present an overview of existing state of the art visualization techniques fur the interactive analysis of results from numerical simulations and measurements. We describe the basic concepts and key ideas behind these different visualization methods in this paper. The potential of these techniques for an efficient integration into a virtual reality environment will be investigated. Furthermore we present our first demonstrator fur visualizing multiparametric data and give an outlook on our plans for further exploiting and developing these techniques in an upcoming project.

• 제어로봇시스템학회:학술대회논문집
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• 1987.10b
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• pp.269-272
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• 1987

This paper is concerned on kinematic analysis and simulation of an automatic feeding mechanism subjected by the motion of a curvilinear inverse cam. The main objection is the development of computer-aided design (CAD) program for simulating the motion of the cam-feeding mechanism using computer-graphics. A computer program CACAFS (Computer-Aided Cam and Automatic Feeding System) is independent of computer hardware used. The program is also interactive using a menu-selection technique. As the second part of the paper for the motion simulation of the cam-feeding system, this paper discusses the state-of-art for CAD. The first part of the paper presents the algorithm to simulate the notion of the cam-feeding mechanism.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06a
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• pp.226-228
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• 2006

In this paper we describe a simulation and development framework for designing mobile 3D graphics architectures. We are developing a simple and flexible simulation and verification environment (SVE) that uses gITrace's ability to intercept and redirect an OpenGL/ES streams. In combination wlth gITrace to trace OpenGL/ES commands, the SVE simulates the behavior of mobile 3D graphics pipeline during playback of traces, and then produces the second geometry trace that can be used as a test vector for the Verilog/HDL RT-level model. By comparing the frame-by-frame results, we can conduct architectural verification. To demonstrate the functionality of the SVE, we show the implementation of the verified mobile 3D architecture on a FPGA board. For this, we also present an application development environment (ADE) includes a mobile graphics API and a device driver interface (DDI). The proposed two software environments, the SVE and the ADE could be used fer developing and testing mobile applications, architectural study and speculative hardware designs.

• Journal of the Korea Computer Graphics Society
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• v.16 no.2
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• pp.1-7
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• 2010

This paper proposes a real-time simulation technique for thin rods undergoing large rotational deformation. Rods are thin objects such as ropes and hairs that can be abstracted as 1D structures. Development of a satisfactory physical model that runs in real-time but produces visually convincing animation of thin rods has been remaining a challenge in computer graphics. We adopt the energy formulation based on continuum mechanics, and develop a modal warping technique for rods that can integrate the governing equation in real-time. This novel simulation framework results from making extensions to the original modal warping technique, which was developed for the simulation of 3D solids. Experiments show that the proposed method runs in real-time even for large meshes, and that it can simulate large bending and/or twisting deformations with acceptable realism.

• Journal of the Korean Home Economics Association
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• v.30 no.1
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• pp.49-65
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• 1992

The writer did a survey of current textile patterns for the purpose of identifying a motif trend. After identifying a current motif trend the writer used an IBM PC 386 Computer and Lumena Software to design actual patterns. The results are as follows: 1. The most common currently used prints are floral patterns. 2. Knowing that floral patterns are most popular, the writer established a motif using the Rose of Sharon, the national flower of Korea. 3. Using computer graphics to move, enlarge and scale-down motif, the writer has been able to design various textile patterns. 4. Creating patterns with computer graphics was not only more efficient, but it also produced more accurate designs and a greater variety of designs. 5. Using the many computer graphic functions avaliable, a greater variety of patterns changes and compositions can be displayed than would be possible if produce by hand. 6. Computer simulations of textiles and clothing made it possible to evaluate the printed fabric or finished product. Faults in the printed fabric or clothing could be corrented before production. Through simulation then it is possible to create higher quality garments and readuce costly mistakes. Thereby greater profits will be realized from the finished garments.

• Journal of the Korea Computer Graphics Society
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• v.25 no.3
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• pp.55-63
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• 2019

Recently, the GPU computing method has been utilized to improve the performance of the physics simulation field. In particular, in the case of a deformed object simulation requiring a large amount of computation, a GPU-based parallel processing algorithm is required to guarantee real-time performance. We have studied the parallel structure design method to improve the performance of the mass spring simulation method which is one of the methods of implementing the deformation object simulation. We used OpenGL's GLSL, a graphics library that allows direct access to the GPU, and implemented the GPGPU environment using an independent pipeline, the compute shader. In order to verify the effectiveness of the parallel structure design method, the mass - spring system was implemented based on CPU and GPU. Experimental results show that the proposed method improves computation speed by about 6,000% compared to the CPU Environment. It is expected that the lightweight simulation technology can be effectively applied to the augmented reality and the virtual reality field by using the design method proposed later in this research.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06a
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• pp.196-198
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• 2006

Shader architecture is one of the fastest growing fields in the ever advancing 3D graphics, and massive amounts of Ideas and technologies are being introduced to the market continuously. In this paper, we present a flexible cycle-accurate simulation environment to accelerate and alleviate the process of developing and verifying these ideas and technologies. Combination of 3D graphics API and hardware simulator allows OpenGL applications to be emulated off-the-shelf for a given shader micro-architecture. Easily modified parameters allow the simulation environment to be tailored to specific demands or requirements.