• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2005년도 연구개발 발표회 논문집
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• pp.441-447
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• 2005

The present study is aimed at understanding the flow physics associated with a safety valve applied to LNG ship engines. One-dimensional gasdynamic analyses and axisymmetric, compressible Navier-Stokes computations have been carried out to provide a qualitative and quantitative knowledge base for an effective design of the safety valve. Gasdynamic forces and thrust coefficients are obtained regarding a change in chamber pressure and distance between the nozzle exit and valve sheet which are major parameters to offer a variation in the flow feature. The present results show that the control of the passage area between the nozzle exit and valve sheet can attenuate the strength of shockwave generated in front of the valve sheet, which causes harm to stable system operation.

• Transactions of the Korean Society of Automotive Engineers
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• 제17권3호
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• pp.1-7
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• 2009

Ethanol has properties of a lower setting point, higher oxygen contents, lower cetane numbers, and also higher volatility compared to biodiesel. Thus, biodiesel fuel can be improved in the fluidity of and exhaust emissions by blended ethanol fuel. This research aims to understand combustion characteristics of biodiesel-ethanol blending fuel inside a constant volume chamber by obtaining some fundamental data in order to improve combustion atmosphere. To understand the physics of combustion, high speed camera was applied to visualize the development of combustion processes, and combustion pressure and exhaust emission were measured at several blending ratios of ethanol and biodiesel fuel. This information may contribute to improve the performance of biodiesel engine and reduce emissions in future.

• Proceedings of the Korean Information Science Society Conference
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• 한국정보과학회 2003년도 가을 학술발표논문집 Vol.30 No.2 (2)
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• pp.718-720
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• 2003

국내 게임 분야의 기술은 업소용 게임장을 중심으로 3차원 영상과 부분적인 체감형 인터페이스를 채용한 게임이 빠른 증가 추세이고, 게임 내용에 따른 재미 요소와 인간의 감각을 매개로 하는 다양한 체감형 반응.조작 장치의 시험적 상용화가 증가되고 있다. 따라서 3D 영상 및 실세계를 정밀하게 실시간으로 시뮬레이션 할 수 있는 물리 엔진의 필요성이 대두되고 있다. 이에 본 논문에서는 PC를 기반으로 한 물리엔진에 대한 설계와 구현 결과에 대해서 서술한다.

• Current Optics and Photonics
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• 제5권1호
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• pp.32-39
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• 2021

We propose a three-dimensional (3D) streaming system based on a lamina display that can convey field information in real-time by creating floating 3D images that can satisfy the accommodation cue. The proposed system is mainly composed of three parts, namely: a 3D vision camera unit to obtain and provide RGB and depth data in real-time, a 3D image engine unit to realize the 3D volume with a fast response time by using the RGB and depth data, and an optical floating unit to bring the implemented 3D image out of the system and consequently increase the sense of presence. Furthermore, we devise the streaming method required for implementing augmented reality (AR) images by using a multilayered image, and the proposed method for implementing AR 3D video in real-time non-face-to-face communication has been experimentally verified.

• Annual Conference of KIPS
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• 한국정보처리학회 2011년도 춘계학술발표대회
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• pp.493-496
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• 2011

최근 소비자가 컴퓨터는 물론 각종 전자기기를 구매하는데 있어 UI(User Interface) 및 UX(User eXperience)가 매우 중요한 요소로 자리 매김하고 있다. 터치스크린이나 각종 센서들이 탑재되고 있는 전자기기에서 볼 수 있듯이 HW의 눈부신 발전과 함께 더불어 UI의 다양성도 확대 되고 있다. 본 논문은 이러한 기대에 부응하기 위해 게임에서 많이 사용되는 물리엔진을 UI에 적용시켜 보았다. 여러 물리엔진들 중에 본 연구에 적합한 Box2D를 채택하여 UI에서 응용 할 수 있는 10가지 모듈을 제시하였으며 활용할 수 있는 예도 제안하였다.

• Annual Conference of KIPS
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• 한국정보처리학회 2023년도 추계학술발표대회
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• pp.731-732
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• 2023

언리얼 엔진 기반의 메타버스나 실시간 게임 환경에서 캐릭터의 맞춤형 동작이 필요한 경우가 있다. 본 논문은 모션 디퓨전 모델을 활용하여 특정 동작을 자동 생성하는 기능을 제공하는 언리얼 엔진 플러그인을 제시한다. 특히 사용자가 텍스트로 신체 동작이나 감정 표현을 기술해 입력값으로 제공하면 서버에서 모션 디퓨전 모델로 애니메이션을 실시간으로 생성한 후, 언리얼엔진 클라이언트에서 후처리하여 사용자의 캐릭터에 실시간으로 적용하는 방식으로 구현했다.

• Annual Conference of KIPS
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• 한국정보처리학회 2008년도 춘계학술발표대회
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• pp.58-61
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• 2008

본 논문에서는 물리엔진 기반으로 지능형 주행 시스템을 구현하여 사용자에게 쾌적한 주행 환경을 제공하여 사용자가 즐거움을 느낄 수 있도록 하는 것에 목적을 두고 있다. 이를 위해 시스템 환경 내에서 사용자의 위치 및 회전각을 추출한 다음 유한 상태 머신과 베이즈 이론에 입각하여 구현된 모듈에 입력하여서 분석을 한다. 그리고 모듈에서 나온 분석 결과를 장애물이나 커브 구역에서 제공 함으로서 사용자가 현 위치에 따른 환경을 인지하여 좀 더 나은 주행을 할 수 있도록 하였다. 또한 시스템 내부적으로 분석된 자료가 주행 시스템에 피드백 과정을 통해 입력되어 자동적으로 환경에 적응하여 주행 시간을 단축하는 시스템을 설계 하였고, 일부 기능에 대한 구현을 완료하였다.

• Journal of the Korean earth science society
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• 제36권6호
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• pp.553-566
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• 2015

The effects of vertical resolutions and planetary boundary layer (PBL) physics schemes in a numerical simulation with a very high resolution over the metropolitan area were investigated. The numerical experiments using the Weather Research and Forecast model were conducted from 0000 UTC 25 October to 0000 UTC 26 October 2013. We verified the numerical results against with six hourly observation data from the radiosonde at Seolleung, which was located in southern part of Seoul, and forty three auto weather systems in Seoul. In the experiments of vertical resolutions in low level atmosphere with 44, 50, and 60 layers, which are set to be subdivided particularly under 2 km height. The experiment in 60 layers, which has the highest vertical resolution in this study, showed relatively a clear diurnal variation of PBL heights. Especially, the difference of PBL heights and 10-meter wind fields were mainly seen in the area of high altitude lands for the experiments of vertical resolution. In the sensitivity experiment of PBL schemes such as asymmetric convective model-version 2 (ACM2), Yonsei University (YSU), and Mellow-Yamada-Janjic (MYJ) to the temperature, all three PBL schemes revealed lower temperature than observed profile from the radiosonde in the entire period. The experiments with YSU PBL and ACM2 PBL schemes show relatively less biased in comparison with the experiment of the MYJ PBL scheme.

• Bulletin of the Korean Space Science Society
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• 한국우주과학회 2007년도 한국우주과학회보 제16권2호
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• pp.139-143
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• 2007

Electric propulsion has become a cost effective and sound engineering solution for many space applications. The success of SMART-1 and MUSES-C developed by European Space Agency (ESA) and Japan Aerospace Exploration Agency (JAXA) each proved that even small spacecraft could accomplish planetary mission with electric propulsion systems. A small electric propulsion system which is Hall effect thruster like SMART-1 is under development by SaTReC and GDPL (Glow Discharge Plasma Lab.) in KAIST for the next microsatellite, STSAT-3. To achieve optimized propulsion system, it is very necessary to understand plasma motions of Hall effect thruster. In this paper, we try to approach comprehensive plasma model with the particle simulation complementary to Particle In Cell (PIC) simulation. We think these two different approaches will help experimenters to optimize Hall effect thruster performances.

• Journal of Korea Game Society
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• 제10권1호
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• pp.127-134
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• 2010

The secondary animation technology for the detailed objects including accessories is being studied and applied to the modern game development. The jiggle-bone deformer is used for 3D graphic tools as a technology to create the animation of these objects, but it is disadvantageous in that the real-time modification is difficult and the graphic developers need much time. The secondary animation can also be realized using a physical game engine, but the cost of animation process increases when many objects in a scene of a game are rendered, and it has a low efficiency. This paper proposes a dynamic jiggle-bone animation algorithm, which can be modified in real time and has the similar effect to the physical game engine. To evaluate the performance of the proposed algorithm, tests were conducted with varied number of bones and for the case of one scene with the animation of many jiggle-bones, and the results were adjudged relatively efficient.