• Journal of the Korean Society of Visualization
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• v.21 no.3
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• pp.85-92
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• 2023

In this study, we present experimental results of cavitating flow around a vortex generator which is used to improve the flow in the wake of ships and enhance propulsion efficiency. We conducted experiments at the CNU cavitation tunnel on a total of six vortex generators, two different aspect ratios and three taper ratios. We recorded cavity patterns using a high-speed camera and quantitatively evaluated cavity fraction using OpenCV. The most important finding of this study is that the vortex cavity generated at a root leading edge of the vortex generator develops at a specific angle.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.321-324
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• 2005

In these days, the management and visualization of 3D geo-spatial information is regarded as one of an important issue in GiS and remote sensing fields. 3D GIS is considered with the database issues such as handling and managing of 3D geometry/topology attributes, whereas 3D visualization is basically concerned with 3D computer graphics. This study focused on the design and implementation for the OpenGL API-based rendering system for the complex types of 3D geo-spatial features. In this approach 3D features can be separately processed with the functions of authoring and manipulation of terrain segments, building segments, road segments, and other geo-based things with texture mapping. Using this implementation, it is possible to the generation of an integrated scene with these complex types of 3D features. This integrated rendering system based on the feature-based 3D-GIS model can be extended and effectively applied to urban environment analysis, 3D virtual simulation and fly-by navigation in urban planning. Furthermore, we expect that 3D-GIS visualization application based on OpenGL API can be easily extended into a real-time mobile 3D-GIS system, soon after the release of OpenGLIES which stands for OpenGL for embedded system, though this topic is beyond the scope of this implementation.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1996.06b
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• pp.88-93
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• 1996

We developed a visualization system for sports broadcasting that informs TV viewers of a sports player's sequential performing forms and locus in detail when gymnastic game such as‘vault’is broadcasted. It records the corresponding frames while a player is performing, extracts only the player's performing forms from background scenes by a proposed algorithm, superposes them sequentially on a background scene, and broadcasts them with slow speed. This system named as‘Multi-Motion’has ever been used in NHK live broadcasting for 1995 World Gymnastics Championships held in Japan.

• Proceedings of the Acoustical Society of Korea Conference
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• 1998.06c
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• pp.239-242
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• 1998

A new real time sound field visualization technique is introduced in this study using PIV(Particle Imaging Velocimetry) technique. Small particles of which density is small enough to follow up the air flow are used for sound visualization. When the driving frequency is in the vicinity of the resonance frequency of the simplified 2-dimensional muffler system, an acoustic streaming is shown and of which velocity distribution is obtained through PIV technique. It is experimentally proved that the present technique is able to visualize and quantify the sound field's energy flow.

• 한국가시화정보학회:학술대회논문집
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• 2003.11a
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• pp.71-74
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• 2003

In this paper, we report the numerical and experimental results in a half-cylinder. In the numerical computation, we used the zonal embedded grid system. Flow visualization for the spin-up flows was used by PIV. The results show that at left hand side an cyclonic cell moves along a wall and separates into both cells at right hand side.

• The Journal of Society for e-Business Studies
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• v.6 no.2
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• pp.13-24
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• 2001

The Real-Time Best-Estimate simulator NPA4K is being developed for providing an efficient nuclear power, KALIMER, simulation environment for transient safety analyses using information visualization. The advanced features of NPA4K simulator are the Once-Through Running Environment, Functionalities of displaying the several X-Y Plot on one system, and Multi-thread Processing, The objective of NPA4K simulator is ta realize the Virtual Reality Environment through Network and Internet technology in Nuclear Power Plants.

• Journal of Navigation and Port Research
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• v.28 no.1
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• pp.17-22
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• 2004

The paper describes implementation of three-dimensional visualization system that is to provide comprehensive meaning of the statistical prediction results on the marine casualties. Graphical User Interface (GUI) and Web based Virtual Reality (VR) technology are mainly introduced in the system development. To provide daily forecasting, time based casualty prediction model and risk level index are developed in this work. As operating test results of the system, complicated statistical meaning can be shown in the three-dimensional virtual space using simple color. In addition, daily risk levels can be shown on the bar-graph.

• Journal of ILASS-Korea
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• v.21 no.1
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• pp.37-46
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• 2016

For the SI engines, at only full load, the pumping loss has a negligible effect, while at part load conditions, the pumping loss increases. To avoid the pumping loss, the spark-ignited engines are designed to inject gasoline directly into the combustion chamber. In the spark-ignited direct-injection engines, ignition probability is important for successful combustion and the flame propagation characteristics are also different from that of pre-mixed combustion. In this paper, a visualization experiment system is designed to study the ignition probability and combustion flame characteristics of spark-ignited direct-injection CNG fuel. The visualization system is composed of a combustion chamber, fuel supply system, air supply system, electronic control system and data acquisition system. It is found that ambient pressure, ambient temperature and ambient air flow velocity are important parameters which affect the ignition probability of CNG-air mixture and flame propagation characteristics and the injected CNG fuel can be ignited directly by a spark-plug under proper ambient conditions. For all cases of successful ignition, the flame propagation images were digitally recorded with an intensified CCD camera and the flame propagation characteristics were analyzed.

• Journal of Power System Engineering
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• v.20 no.2
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• pp.32-42
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• 2016

Under part load condition of spark-ignition engine, pumping loss had great effect on engine efficiency. To reduce pumping loss, the study designed spark-ignited engines to make direct spray of gasoline to combustion chamber. In spark-ignited direct-injection engines, ignition probability is important for successful combustion and flame propagation characteristics are also different from pre-mixed combustion. This study designed a visualization testing device to study ignition probability of spark-ignited direct-injection LPG fuel and combustion flame characteristics. This visualization device consists of combustion chamber, fuel supply system, air supply system, electronic control system and data acquisition system. Ambient pressure, ambient temperature and ambient air flow velocity are important parameters on ignition probability of LPG-air mixture and flame propagation characteristics, and the study also found that sprayed LPG fuel can be directly ignited by spark-plug under proper ambient conditions. To all successful cases of ignition, the study recorded flame propagation image in digital method through ICCD camera and its flame propagation characteristics were analyzed.

• Korean Institute of Interior Design Journal
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• v.16 no.4
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• pp.119-126
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• 2007

A prototype design process visualization and guidance system, is being developed. Its purpose is to visualize the design process in more intuitive manner so that one can get an insight to the complicated aspects of the design process. By providing a tangible utility to the design process performed by the expert designers or guided by the system, novice designers will be greatly helped to learn how to approach a certain class of design. Not only as an analysis tool to represent the characteristics of the design process, the system will be useful also for learning design process. A design ontology is being developed to provide the system with a knowledge-base, representing designer's activities associated with various design information during the conceptual design process, and then to be utilized for a computer environment for design analysis and guidance. To develop the design ontology, a conceptual framework of design activity model is proposed, and then the model has been tested and elaborated through investigating the nature of the early conceptual design. A design process representation model is conceptualized based on the ontology, and reflected into the development of the system. This paper presents the development process of the visualization system, modeling of design process ontology, and how the system could be utilized for the analysis and learning of conceptual design methods using computer mediated design support environment.