• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.139-142
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• 2008

Developing from stereoscopic to autostereoscopic, researchers on display technology are trying to provide more depth cues to viewer, leading to the advent of true 3D display. Volumetric 3D displays seem to be practical technology at present. Ultimate display will function like human vision system, with characteristics of providing all depth cues and free interaction.

• International Journal of Contents
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• 제14권2호
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• pp.41-44
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• 2018

In this paper, we propose a novel method for developing expressive typography authoring tools with personal emotions. Our goal is to implement an interactive typography system that does not rely on any particular language and provides an easy, natural user interface and allows for immediate interaction. For this purpose, we converted the text data entered by a user to image data. The image data was then used for interaction with the user. The data was synchronized with the user's skeleton information obtained from the depth camera. We decomposed the characters using the formality of language to provide a typographical movement that responds more dynamically to the user's motion. Thus, this system provides interaction as a unit of characters rather than as a whole character, allowing the user to have emotional and aesthetic emotional immersion into his or her creation.

• 한국방사선학회논문지
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• 제17권1호
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• pp.31-36
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• 2023

소동물 전용의 영상 및 치료기기 중 양전자방출단층촬영기기(positron emission tomography, PET)는 관심 시야 내에서 공간분해능의 변화가 발생한다. 이는 작은 갠트리와 작고, 긴 섬광 픽셀을 사용함으로써 발생하는 현상으로 이를 해결하기 위해 반응 깊이를 측정하는 검출기들이 개발 및 연구되고 있다. 본 연구에서는 여러 개의 섬광체 블록과 서로 다른 반사체 패턴을 지닌 광가이드를 사용하여 반응 깊이를 측정하는 검출기를 설계하였다. 3 mm × 3 mm × 5 mm의 섬광 픽셀을 4 × 4 배열로 구성한 섬광체 블록이 4개의 층을 이루고, 각 층마다 광가이드를 삽입하여 전체 검출기를 구성하였다. 반응 깊이 측정 여부를 확인하기위해, 모든 섬광 픽셀의 중심에서 감마선 반응을 발생시켜 데이터를 획득 후 평면 영상으로 재구성하였다. 층 사이에 삽입된 광가이드의 반사체 패턴이 모두 달라 각 층별 섬광 픽셀의 위치가 서로 다른 곳에 형성되었다. 이렇게 형성된 섬광 픽셀의 위치를 모두 분리하여 영상의 재구성에 사용하면 관심시야 모든 영역에 걸쳐 고른 공간분해능을 달성할 수 있을 것으로 판단된다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2010년도 추계학술대회
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• pp.343-344
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• 2010

마커리스 시스템의 경우 2차원 영상에서 깊이 값을 추정하기 위해서는 스테레오 비젼과 같이 고가의 장비를 통해 깊이 값을 추정하였다. 이에 단안 영상에서 깊이 값을 추정하여 객체를 증강하기 위해 소실점을 추출하고 상대적 깊이 값을 추정한다. 객체 증강에 있어 향상된 몰입감을 얻기 위해서는 가상의 객체들이 거리에 따라 서로 다른 크기로 그려져야 한다. 본 논문에서는 획득한 영상에서 소실점을 생성하고 깊이정보를 이용하여 증강된 객체를 서로 다른 크기로 증강하여 객체간 상호 몰입감을 향상시켰다.

• Earthquakes and Structures
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• 제5권6호
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• pp.679-702
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• 2013

During an earthquake, soils filter and send out the shaking to the building and simultaneously it has the role of bearing the building vibrations and transmitting them back to the ground. In other words, the ground and the building interact with each other. Hence, soil-structure interaction (SSI) is a key parameter that affects the performance of buildings during the earthquakes and is worth to be taken into consideration. Columns are one of the most crucial elements in RC buildings that play an important role in stability of the building and must be able to dissipate energy under seismic loads. Recent earthquakes showed that formation of plastic hinges in columns is still possible as a result of strong ground motion, despite the application of strong column-weak beam concept, as recommended by various design codes. Energy is dissipated through the plastic deformation of specific zones at the end of a member without affecting the rest of the structure. The formation of a plastic hinge in an RC column in regions that experience inelastic actions depends on the column details as well as soil-structure interaction (SSI). In this paper, 854 different scenarios have been analyzed by inelastic time-history analyses to predict the nonlinear behavior of RC columns considering soil-structure interaction (SSI). The effects of axial load, height over depth ratio, main period of soil and structure as well as different characteristics of earthquakes, are evaluated analytically by finite element methods and the results are compared with corresponding experimental data. Findings from this study provide a simple expression to estimate plastic hinge length of RC columns including soil-structure interaction.

• Computers and Concrete
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• 제27권1호
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• pp.1-12
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• 2021

This work presents a safety assessment of an underground tunnel subjected to a ballistic missile attack employing the numerical approach. For the impact simulation, a box shaped reinforced concrete (RC) structure with a cross section dimension of 8.0×10.0 m under a soil layer that was attacked by a SCUD missile was modeled using finite element (FE) software LS-DYNA. SCUD missile is one of a series of tactical ballistic missiles developed by Soviet Union during the Cold War, which is adopted for a short-range ballistic missile. The developed FE simulation for the penetration depth of the missile impacting into the soil structure was verified from the well-known formula of the penetration prediction. The soil-structure interaction, the soil type, and the impact missile velocity effects on the penetration depth of the missile into the different soil types were investigated. The safety assessment of the underground tunnel was performed with regard to the different depths of the underground tunnel. For each missile velocity and soil type, a specific depth called the unsafe depth was obtained from the analysis results. The structure beneath the soil beyond this depth remains safe. The unsafe depth was found to be increased with the increasing missile velocity.

• 대한기계학회논문집B
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• 제20권9호
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• pp.2944-2952
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• 1996

In this paper the CSCM type upwind flux difference splitting Navier-Stokes method has been applied to study the ARL-SL19 transoni $c^ersonic compressor cascade flow. First, the general characteristics of baseline cascade flow were analyzed. At freestream Mach n.1.612 and exit/inlet pressure ratio 2.15, the results from current laminar flow were compared well in suction surface with the experiment; however, not well in pressure surface. Second, numerical study of the transoni $c^ersonic compressor cascade flow demonstrated the effectiveness of a passive control by the various size cavities. A cavity under the shock foot point at the suction surface of the blades was used as a passive control. The passive control of shock-boundary layer interaction by a cavity reduced total pressure losses. The effect of cavity length and depth was studied. The total pressure loss was reduced by about 10% and the isentropic efficiency was improved slightly. The effect of cavity depth in current study(d/l = 0.05, 0.02) was not found strong. Further adequate turbulence modeling and TVD schemes would help to capture the shock more accurately and increase the effectiveness of the current shock-boundary layer interaction study using upwind flux difference splitting computational methods.thods.

• 한국컴퓨터정보학회논문지
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• 제17권4호
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• pp.51-58
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• 2012

최근 깊이영상을 기반으로 한 3D 기술이 3D 공간감지, 3D 영상획득, 3D 인터랙션, 3D 게임 등 다양한 분야에서 응용되고 있다. 깊이영상을 생성하기 위해서는 깊이 카메라를 이용하게 되는데, 이렇게 생성된 깊이영상의 화질을 개선하기 위한 다양한 시도들이 이루어지고 있다. 본 눈문에서는 이러한 깊이 카메라 기반의 3D 응용에 있어서 깊이 영상을 개선하기 위해 영역기반의 에지 검출기를 사용하는 방법을 제안한다. 제안된 방법은 제한된 환경에서의 깊이영상을 획득하는 과정에서 발생 할 수 있는 화질열화를 후처리 또는 전처리를 통해 개선함으로써 보다 향상된 깊이 영상을 제공한다. 다양한 실험결과를 통해서 개선된 깊이영상을 객관적 화질 평가를 위해 가상시점 참조 소프트웨어에 적용하여 비교함으로써 최대 0.42dB의 화질 향상을 확인하였다. 또한 영상의 실제 시청 환경과 가장 유사한 방법인 DSCQS(Double Stimulus Continuous Quality Scale)방법을 통해서 주관적 화질의 객관적 평가를 수행함으로써 개선된 깊이영상의 효용성을 다시 확인하였다.

• 한국간호교육학회지
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• 제18권2호
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• pp.323-331
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• 2012

Purpose: Level of meta-cognition of students has been regarded as one of the crucial factors on web-based learning. This study aimed to describe interaction type in small group discussion of the nursing graduate students and to investigate learning consequences and interaction types in group discussion on meta-cognition level. Method: Twenty six graduate nursing students attending the class on-line at the K university in Seoul were included in the study. We measured their meta-cognition level and learning attitude. We also scored their individual and group reports as well as analyzed interaction type by reviewing the dialogue of the group discussion. Results: The participants showed low frequency of exploratory interaction and high frequency of integrative interaction in the cognitive interaction category. They showed frequent modification interaction in the meta-cognitive interaction category. Interestingly, the students with lower level of meta-cognition achieved significantly greater scores in the individual assignments. High functioning group consisting of the students with high meta-cognitive level produced greater group report. Conclusion: A new strategy is needed to encourage in-depth interaction in a group discussion of nursing students. Meta-cognitive level of the students should be considered to form a small group for discussion in order to improve group activities.

• 한국멀티미디어학회논문지
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• 제14권2호
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• pp.329-338
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• 2011

증강현실에서 다양한 미디어의 결합으로 보다 향상된 현실감 있는 멀티미디어 데이터가 요구되고 있다. 기존의 미디어 정보에 텍스트 및 음성과 비디오 등 다양한 미디어를 결합한 멀티미디어 정보에 대한 첨단 기술이 미디어 산업 전반에 주도적인 위치를 점하고 있다. 특히 인터넷에서의 다양한 의사전달 수단 및 시각화에 대한 관심과 가상공간에서의 의사 표현을 위한 실시간 상호작용 시스템 구축 및 3차원 콘텐츠, 증강현실 기술에 대한 서비스 요구가 증가되고 있다. 이러한 서비스들은 기존 콘텐츠에서 입체감 형성을 위한 3차원 공간구조의 복원에 필요한 깊이 값 생성에 어려움이 있다. 그러므로 2차원 영상을 이용하여 효율적인 Depth-map 생성에 관한 연구가 필요하다. 본 논문에서는 2차원 영상을 이용하여 3차원 공간구조 복원에 필요한 Depth-map 생성기법의 단점을 보완하여, 기존 알고리즘에서 정의 되지 않은 영상 내 소실점 위치에 따른 갚아 방향의 정의를 통한 개선된 Depth-map 생성 기법을 제안하였다.