• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.02a
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• pp.73-81
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• 2004

National Geographic Information Institute (NGII) in Korea, through National Geographic Information System (NGIS) Program, has prepared to generate and disseminate digital elevation data for Korea. This is a pilot research to propose a policy for generation, maintenance, and supply of Korea Digital Elevation Data (KDED). Customer demands for accuracy and resolution of DEM was surveyed through questionnaire. In order to investigate the quality, the technical efficiency and the production cost, a tentative DEM in a small test site was generated based on digital topographic maps (original paper map scale 1 :5,000), analytical plotter, and LIDAR. Accuracy standard for KDED was derived based on source data and generation methods. As results of this research, we recommend uniformly spaced grid model for KDED. Its preferable grid space is 5m in urban and its vicinity; and 10m in field and mountainous area. LIDAR has been valuated as a proper KDED generation method fulfilling customers demand for the accuracy.

• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.1
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• pp.151-163
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• 2013

Recently the attention on digital hologram that is regarded as to be the final goal of the 3-dimensional video technology has been increased. Digital hologram is calculated by modeling the interference phenomenon between an object wave and a reference wave. The modeling for digital holograms is called by computer generated hologram (CGH) Generally, CGH requires a very large amount of calculation. So if holograms are generated in real time, high-speed method should be needed. In this paper, we analyzed CGH equation, optimized it for mapping general purpose graphic processing unit (GPGPU), and proposed a optimized CGH calculation technique for GPGPU by resource allocation and various experiments which include block size changing, memory selection, and hologram tiling. The implemented results showed that a digital hologram that has $1,024{\times}1,024$ resolution can be generated during approximately 24ms, using 1K point clouds. In the experiment, we used two GTX 580 GPGPU of nVidia Inc.

• Asia pacific journal of information systems
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• v.30 no.4
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• pp.808-831
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• 2020

The business world has been undergoing a digital transformation. The adoption of multi-sided digital platform across the world has sped up this transformation. Multi-sided digital platforms create value by mediating interactions and transactions of distinct groups of users. A platform and its stakeholders need to be considered as a business ecosystem. Elements or components in the ecosystem exchange values and together form a network of exchange values. The objective of this paper is to construct a framework for crafting and observing digital business ecosystems. The foundation theories used to construct the framework are transaction cost economy (TCE), multi-sided markets, and value network. This paper uses Go-Jek, a growing ride-hailing platform from Indonesia, as a case to discuss how the framework works in mapping Go-Jek's digital business ecosystem, and then explain its expansion strategy. This paper has both theoretical and managerial contributions. It provides a formal definition of digital business ecosystems as a network of exchange values. The framework does not only help studies the existing business ecosystems but also can be used to craft a new business ecosystem. It can also be used to study value exchanges within the ecosystem, assessing or crafting ecosystem expansion strategies.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.1
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• pp.117-124
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• 2010

Lots of changes in Weolmido have occurred in the historical and cultural aspects owing w the geographical features. This study aims at restoring Weolmido to the past shape three-dimensionally and analyzing its changes. For achieving this goal, I made use of paper maps made in 1918, 1928, and 1969, a digital map produced in 2008, and aerial photos photographed in 1954. And I attempted to grasp the architectural shape and the topographical limn by using photos in those times and put them to practical use for restitution. Image restitution was carried out under the method of mapping and photogrammetry. As the result of restitution, I could restore each shape of Weolmido for those past times to the original condition three-dimensionally and catch its changes according to the difference of times.

• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.535-540
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• 2006

집적 영상(Integral Imaging) 시스템은 관찰자가 특수안경의 착용 없이 육안으로 3 차원 영상을 볼 수 있는 무안경식 양안시차 디스플레이 방식 중 하나로, 수직, 수평 시차와 총천연색의 영상을 제공한다. 집적영상 시스템은 3 차원 정보를 2 차원 엘리멘탈 이미지 (Elemental image)의 형태로 저장하는데, 엘리멘탈 이미지는 조금씩 다른 방향에서 제한된 크기로 촬영된 이미지이다. 엘리멘탈 이미지는 컴퓨터 그래픽으로 만들어질 수도 있는데, 이를 이용하는 집적 영상 방식을 CG 직접 영상 시스템이라 한다. 이와 같이 컴퓨터 계산에 의해 엘리멘탈 이미지를 얻는 과정을 이미지 매핑 (Image mapping)이라 부른다. 이제까지 제안된 이미지 매핑 방식에는 점대점 (Point to Point), MVR (Multi-Viewpoint Rendering), PGR (Parallel Group Rendering) 이 있다. 그러나 이런 방식들은 계산량이 많거나 렌즈 어레이 개수의 증가에 의해 속도에 영향을 받는 단점이 있어, 아직 가상현실 같은 실시간 CG 응용 분야에 사용하기 어려운 문제가 있다. 본 논문에서는 VVR (Viewpoint Vector Rendering)이라는 기존의 방법과 비교해 향상된 새로운 이미지 매핑 방법을 제안한다. 먼저 VVR 개념을 자세히 설명한 후 VVR 을 사용한 집적 영상 시스템을 구현하여 MVR 방법과 비교 분석한 실험결과와 개선되어야 할 방향을 제시한다.

• Journal of Digital Convergence
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• v.11 no.5
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• pp.313-318
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• 2013

QoS in wireless multimedia sensor networks is an important issue to enhance streaming media service. This paper proposes a new 2-layer based QoS evaluation scheme for enhancing the streaming media QoS of wireless multimedia sensor networks. The proposed scheme performs the fuzzy relevance to control the streaming between application layer and network layer, and it performs 2-layer mapping process to enhance the transmission reliability and throughput. The simulation results show that the proposed scheme achieves improved performance in packet control ratio, transmission reliability, and delay overhead ratio compared with those of other existing schemes.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.23 no.6 s.165
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• pp.988-1000
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• 1999

An experimental study is presented for the effect of number of terms of a pewee series type stress function on stress analysis around a hole in tensile loaded plate. The hybrid method coupling photoelastsic data inputs and complex variable formulations involving conformal mappings and analytical continuity is used to calculate tangential stress on the boundary of the hole in uniaxially loaded, finite width tensile plate. In order to measure isochromatic data accurately, actual photoelastic fringe patterns are two times multiplied and sharpened by digital image processing. For qualitative comparison, actual fringes are compared with calculated ones. For quantitative comparison, percentage errors and standard deviations with respect to percentage errors are caculated for all measured points by changing the number of terms of stress function. The experimental results indicate that stress concentration factors analyzed by the hybrid method are accurate within three percent compared with ones obtained by theoretical and finite element analysis.

• International Journal of Ocean Engineering and Technology Speciallssue:Selected Papers
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• v.6 no.1
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• pp.22-29
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• 2003

This research aims at investigation of accuracy potential of RTK(Real-Time Kinematic) GPS in combination with Echo Sounder(E/S) for the coastal mapping. Apart from this purpose, the accuracy of ambiguity resolution with the OTF(On The Fly) method was tested with respect to the initialization time. The result shows that the accuracy is better than 1cm with 5-minute initialization in the distance of 10km baseline. The seaside topography was measured by the RTK GPS only, on the other hand the seafloor topography was surveyed in combination of RTK GPS and E/S. Comparing to the volume of seaside measured by RTK GPS and digital topographical map, the difference of only 2% was achieved. This indicates that the coastal mapping. As a result, it has been revealed that every possible noise in surveying could be corrected and the accuracy could be improved. The accuracy of GPS data acquired in real time was as good as that acquired by post processing. It is expected that it will be useful for the analysis of coastal geographic characteristics because DTM(Digital Terrain Model) can be also constructed for the harbor reclamation, the dredging, and the variation of soil movement in a river.

• Journal of Digital Contents Society
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• v.9 no.4
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• pp.751-758
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• 2008

The purpose of this study is to implement 3D Face Model, which resembles a user, using 3D Graphic techniques. The implemented 3D Face model is used to further study and implement 3D Facial Aesthetic Surgery System, that can be used to increase the satisfaction rate of patient by comparing before and after facial aesthetic surgery. For designing and implementing 3D Facial Aesthetic Surgery System, 3D Modeling, Texture Mapping for skin, Database system for facial data are studied and implemented independently. The Detailed Adjustment System is, also, implemented for reflecting the minute description of face. The implemented 3D Facial Aesthetic Surgery System for this paper shows more accuacy, convenience, and satisfaction in compare with the existing system.

• The Journal of the Korea Contents Association
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• v.12 no.9
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• pp.48-56
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• 2012

The interaction using digital media has been widely utilized in modern art. In particular, network based digital media enables two-way and real-time communication regardless of time and place. Network is possible to connect to effective and meaningful communication of extended relationship. This study proposes novel human-MediaFacade interaction method through a mechanism on interworking between 3D mapping technology and social media, smart devices. This study has an important meaning which can be set multi-user interaction. And a study of creating 'Facade' which interaction has high artistic value.