• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.288-289
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• 2009

Using a mechano-luminescent (ML) material enabling the visualization of fast propagating cracks with bridging or transformed wake evolutions under a conventional loading condition, the quasi-dynamic fracture mechanisms in association with two different types of crack wake developments wewe investigated in various ceramic.

• Journal of the Korean Society of Safety
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• v.27 no.6
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• pp.93-98
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• 2012

In order to capture the fast crack propagation in an unmanipulated concrete fracture test, we employed mechanoluminascent(ML) material, which emits visible light when stressed, as a crack visualization tool. Three-point bending fracture test setup, a paint type ML material and a high speed camera were used to capture the images of fast moving cracks. The maximum size of coarse aggregates of concrete was used as an experimental parameter. The crack images, loading, and crack mouth opening displacement were successfully recorded as a function of time elapsed. From the test results, several interesting cracking behavior in the unmanipulated fracture test was observed in such that (1) the crack moves fast while the load is slowly decreased after the maximum loading, and (2) the crack in concrete with larger coarse aggregates moves faster than the others.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.1
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• pp.25-33
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• 1998

An experimental study has been carried out to obtain optimal conditions for turbulent mixing of two fluid streams at various angle branches by a flow visualization method. The main purpose of this study is the utilization of flow visualization method as a fast and efficient way to find the optimal mixing conditions when several flow control parameters are superimposed. It is verified that the optimal conditions estimated by flow visualization method have good agreement with the concentration field measurements. The results demonstrate that the diameter ratio is mainly attributed to the mixing phenomena than the branch pipe angle and the Reynolds number. The most striking fact is that there exists the best diameter ratio, d/D.ident. O.17, which requires the minimum momentum ratio in the range of the present experiment. The velocity ratio for the optimal mixing condition has a value within 2 to 16 according to the different flow parameters.

• Journal of the Korean Society of Visualization
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• v.14 no.3
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• pp.51-58
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• 2016

New concept spark plug was developed to study its influence on the combustion characteristics of SI engine. It has pre-ignition chamber at the lower end of spark plug and flame hole, in which fresh mixture gas can be put in through the flame hole without any fuel supply system. This spark plug was tested in a single cylinder engine dynamometer for different air fuel ratio to measure the fuel consumption rate, emission gases, and MBT timing. And constant volume combustion chamber was made to understand flame characteristics of spark plug. New spark plug induced fast burn compared to the conventional spark plug and its effects were increased in lean air fuel ratio. Pre-ignition chamber spark plug with 5 holes which had adjusted size was more stable and effective in combustion performance than pre-ignition chamber spark plug with 1 hole. And its effects showed larger differences in lean air fuel ratio than stoichiometric condition. Flame kernel and flame growth process of conventional spark plug and pre-ignition chamber spark plug studied by flame visualization of schlieren method.

• Archives of design research
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• v.16 no.3
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• pp.143-150
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• 2003

An icon which is used in website as a role of a mark is an important device, what is called, to find the contents The users get satisfied with their internet surfing when visualization of icon has exactly the right content. Therefore, visualization of contents - performing more fast and more convenient functions in searching a right content which a user want - becomes much more important. In this study, we researched the expressive ways of con indicating the common contents in the website, we divided into a visible and an invisible content, analysed the cases in symbolic situation and finally suggested the most appropriate method of visualization in each type.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10a
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• pp.33-35
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• 1999

인터넷의 발달과 더불어 매일같이 제공되는 수많은 정보로부터 자신에게 필요한 정보만을 추출하는데는 많은 시간과 노력이 소모된다. 이러한 정보수집의 어려움에서 정보를 쉽고 효율적으로 찾기 위해서 웹 문서 시각화 시스템을 구현하였다. 웹 문서 시각화 시스템은 사용자가 검색하는 정보는 과거에 검색했던 웹 문서를 다시 방문하는 경험에서 착안하였다. 이를 위해 인터넷 익스플로러를 통해서 방문 중인 웹 문서의 URL, 키워드, 문서간의 유사성을 추출하여 시각화 한다. 시각화 알고리즘으로 FastMap을 사용하였다. 본 논문에서 FastMap은 웹문서간의 유사성, 즉 상대적인 거리 객체 형태를 2-차원 공간으로 표현하는 알고리즘이다. 2차원 공간으로 매핑된 주변에 있는 웹 문서 객체들을 확대하면 방문중인 웹 문서와 유사성이 있는 문서를 쉽게 찾을 수 있다.

• The KIPS Transactions:PartA
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• v.9A no.4
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• pp.581-588
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• 2002

In implementing interactive multimedia systems, real-time visualization plays an important role. This paper presents efficient data structures and algorithms for real-time terrain navigation. Terrain data set is usually too huge to display as is. Therefore LOD (levels of detail) methods and view frustum culling are essential tools. This paper describes in detail compact hierarchical data structures, fast view frustum culling, and efficient LOD construction/rendering algorithms. Unlike previous works, we use a precise screen-space error metric for vertex removal and a strict error threshold allowing sub-pixel -sized errors only. Nevertheless, we can achieve 22 fps on average in a PC platform. The methods presented in this paper also satisfy almost all of the requirements for interactive real-time terrain Visualization.

• Current Optics and Photonics
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• v.5 no.6
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• pp.699-710
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• 2021

In this study, we propose a biomimetic optical structure design methodology for investigating micro-optical mechanisms associated with the compound eyes of insects. With these compound eyes, insects can respond fast while maintaining a wide field of view. Also, considerable research attention has been focused on the insect compound eyes to utilize these benefits. However, their nano micro-structures are complex and challenging to demonstrate in real applications. An effectively integrated design methodology is required considering the manufacturing difficulty. We show that photorealistic ray-traced visualization is an effective method for designing the biomimetic of a micro-compound eye of an insect. We analyze the image formation mechanism and create a three-dimensional computer-aided design model. Then, a ray-trace visualization is applied to observe the optical image formation. Finally, the segmented images are stitched together to generate an image with a wide-angle; the image is assessed for quality. The high structural similarity index (SSIM) value (approximately 0.84 to 0.89) of the stitched image proves that the proposed MATLAB-based image stitching algorithm performs effectively and comparably to the commercial software. The results may be employed for the understanding, researching, and design of advanced optical systems based on biological eyes and for other industrial applications.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.04a
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• pp.743-744
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• 2012

• Journal of Navigation and Port Research
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• v.34 no.3
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• pp.153-160
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• 2010

Simulation visualization technology is an important constituent through which users directly interact with simulators. Simulator users have a needs for more fast, realistic and intuitive visualization. Though hardware-related performances such as computing power and visual equipment have been grown, the limits have existed in graphics rendering engines generally used in marine simulator up to now. This paper has focused on the review of graphic rendering engines available for simulation visualization. We had deduced system requirements for visualization of ship handling simulation, had surveyed graphic rendering engines as commercial and open source, and analyzed strengths and weakness of them. The feasibility study for simulation visualization of tug-barge transportation with an open source graphics rendering engine(OGRE3D) has been demonstrated.