• International Journal of Contents
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• v.10 no.3
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• pp.9-16
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• 2014

Depth-image-based rendering is generally used in real-time 2D-to-3D conversion for 3DTV. However, inaccurate depth maps cause flickering issues between image frames in a video sequence, resulting in eye fatigue while viewing 3DTV. To resolve this flickering issue, we propose a new 2D-to-3D conversion scheme based on fast and robust depth-map generation from a 2D video sequence. The proposed depth-map generation algorithm divides an input video sequence into several cuts using a color histogram. The initial depth of each cut is assigned based on a hypothesized depth-gradient model. The initial depth map of the current frame is refined using color and motion information. Thereafter, the depth map of the next frame is updated using the difference image to reduce depth flickering. The experimental results confirm that the proposed scheme performs real-time 2D-to-3D conversions effectively and reduces human eye fatigue.

• Journal of Korea Multimedia Society
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• v.11 no.8
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• pp.1160-1168
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• 2008

Recent technological innovations of mobile hardware which make it possible to implement real-time 3D rendering effects under mobile environment have provided a potential to develop realistic mobile application programs. This paper presents platform independent, OpenGL ES based, real-time mobile rendering libraries, called DMGL for supporting high quality 3D rendering on handhold devices. The libraries allows the programmers who develops mobile graphics softwares to generate varying advanced real-time 3D graphics effects without great effort. Moreover, GPGPU-based libraries give a set of functions to solve complex equations for simulating natural phenomena such as smoke and fire, and to render the results in real-time.

• The Journal of the Korea Contents Association
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• v.12 no.9
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• pp.1-8
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• 2012

In this paper, we propose a rate-distortion optimization method to improve the coding efficiency of the conventional 3D-DCT based compression method using adaptive block mode selection for integral images. In the conventional 3D-DCT based compression method, 3D-DCT blocks of variable block sizes are adaptively selected depending on the characteristics of integral images, and then 3D-DCT is performed. The proposed method applies a rate-distortion optimization to determine the optimal block mode. In addition, we suggest the optimal Lagrangian parameter for integral images. Experimental results show that the proposed method gives bit-rate reduction of about 5%.

• Proceedings of the Korean Society of Computer Information Conference
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• 2010.07a
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• pp.23-26
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• 2010

In this paper, we propose a new method for the design and implementation of a web-based 3D fashion shopping mall. Web 3D shopping mall is implemented by using a Web3D authoring tool, ISB, which provides easy mouse operation. 3D human models and cloth item model are designed by low polygon modeling method of 3D MAX. The designed 3D human models and cloth item model are exported to XML file. Finally, 3D human models and cloth item model are displayed and animated on the Web by using ActiveX control based on DirectX. We also implemented textile palette and mapped it to clothes model by using alpha blending during simulation.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.46 no.2
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• pp.106-113
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• 2009

Recently, due to many industrial accidents at construction sites, a variety of researches for structural health monitoring (SHM) of buildings are progressing. For real site application of SHM, one of the advanced technologies has blown as wireless sensor networks (WSN). In this paper, we proposed WIVA(WSN Monitoring framework based on 3D Visualization and Augmented Reality in Mobile Devices) system that applies 3D visualization and AR technology to mobile devices with camera based on WSN in order to expand the extent of information can observe. Moreover, we performed experiments to validate effectiveness in 3D and AR mode that utilize WSN data based on IEEE 802.15.4. In real implementation scenario, we demonstrated a fire occurrence test in 3-story building miniature.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.4
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• pp.477-482
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• 2015

In this paper, an android platform with Unity engine was proposed for the effective 3D presentation of IoT sensor's position to IoT(Internet of Things) users. This android platform based home-gateway was designed with the cooperation of 3D unity engine for 3D texture according to MovieTexture simultaneously. As a result, the 3D presentation technology of IoT sensors was described with Unity based 3D modeling. In this proposed smart gateway, the 3D position was presented with the received RSSI(Received Signal Strength Indicator) and angle of IoT sensors. This 3D Unity launcher can be used for the 3D position, monitoring, and the life managing of IoT sensors with the beacon and 3 dimensional cube-style after the 3D conversion of 2D.

• Journal of KIBIM
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• v.9 no.3
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• pp.30-40
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• 2019

Extraction of fabrication documents is very important because it provides information related to tasks of fabrication and construction. Therefore, in the case of a prefabricated member such as a steel structure, it is necessary to improve the productivity of fabrication documents through 3D BIM. However, research and evidence data on direct comparison analysis of 3D BIM-based documents extraction versus 2D CAD-based documents extraction are hard to find. Thus, this study focuses on productivity analysis of 3D BIM based fabrication documents extraction. In this study, the productivity data of fabrication documents extraction for module construction of EPC project was analyzed. For the productivity analysis, a case study on the fabrication documents of Module A (1,965 sheets) and Module B (1,216 sheets) was conducted. Fabrication documents for each module include general arrangement drawing, assembly drawing, single part drawing and single plate drawing. Comparison of 2D CAD based fabrication documents extraction and 3D BIM based fabrication documents extraction, the productivity for the entire work was improved from 17 hours to 16 hours for Module A and 12 hours to 7 hours for Module B. Especially, the productivity of the assembly drawings, which occupies a large part of the fabrication documents, was improved by about 48.75% from the total time required from 281 hours to 144 hours.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.04a
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• pp.188-189
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• 2022

With the development of nano-reinforcement technology, TiO₂ nanomaterials have received widespread attention as one of the additives without pozzolanic reaction, which can be used to improve the mechanical properties of cement-based materials. Meanwhile, with the development of additive manufacturing technology or known as 3D printing technology, its application in the construction field has also got noticed. Therefore, in this work, the effect of three sizes of TiO₂ on the compressive strength of hardened cement-based materials fabricated by binder jetting 3d printing was evaluated. According to the results, the TiO₂ particles with larger sizes can provide better reinforcement to the hardened cement due to its more significant filling effect.

• Korean Journal of Heritage: History & Science
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• v.55 no.3
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• pp.6-20
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• 2022

The restoration of cultural heritage materials is an important research theme. This study improved the existing cultural heritage restoration method and attempted to establish a restoration system for cultural heritage data based on historical documents and visual materials. Recognizing the limitations of existing studies, this paper attempted to restore cultural heritage data through interdisciplinary research. In addition, 3D restoration was carried out after restoration in 2D form based on literature documents rather than existing visual sources. The object of restoration that was selected was "Jeol," which represents the power of the king of Koguryo. Koguryo's Jeol is a type of flag. Jeol appears in the mural in Anak Tomb No. 3. Rather than using only photographic materials of murals, the restoration was carried out through cross-validation of literature data and materials on archaeological art history. This is important in that the restoration carried out in this study is an accurate restoration with a historical understanding based on the literature of the relevant cultural heritage. In this study, a restoration process based on historical records was established. A 3D restoration process was performed by adding and applying visual materials after the object was first shaped based on the literature data. Restoration based on literature and visual materials was carried out based on interdisciplinary research. Therefore, this study aims to build a digital restoration system for cultural heritages and to contribute to spreading the 3D digital restoration research of cultural heritages that can be applied to various platforms.

• Proceedings of the Optical Society of Korea Conference
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• 2009.10a
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• pp.133-134
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• 2009

We have presented our approach to build a 3D display system based on digital holography. For wide viewing angle, we have presented several techniques such as measurement, time-sharing display, and coherent amplification. These techniques can advance the wavefront 3D display system to next stage.