• International Journal of Internet, Broadcasting and Communication
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• v.7 no.2
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• pp.16-27
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• 2015

Holography technology which was developed by Dennis Gabor (1900~1979) in 1948 is a technology to record wave planes of actual 3D objects. It is known as the only technology which can express 3D information most perfectly close to human-friendly. Holography technology is widely used in advertisement, architecture and arts as well as science technology areas. Especially, digital holographic print which is an applied area is greatly used in military map, architecture map and cultural asset restoration by printing and reproducing 3D information. Holography is realized by recording and reproducing the amplitude and phase information on high resolution film using coherent light like laser. Recording materials for digital holographic printer are silver halide, photoresist and photopolymer. Because the materials have different diffraction efficiency according to film characteristics of each manufacturer, appropriate guide lines should be suggested through efficiency analysis of each film. This paper suggests appropriate guide lines through the diffraction efficiency measurement of silver halide which is a holographic printer recording medium. And the objective of this study is to suggest appropriate guide lines through diffraction efficiency analysis of Ultimate 08-C and PFG-03C which are commercially used. The experiment was prepared by self-diffraction efficiency system which measures the strength with the defector by penetrating RGB recording medium and concentrating diffracted beams through collimating lens. The experiment showed Geola's PFG-03C which is a silver halide for full color has price/performance advantage in optical hologram recording, but recording angles and reproduction angles are irregular for digital holographic printer recording. Ultimate's Ultimate08-C for full color shows its diffraction efficiency is relatively stable and high according to recording angles and laser wavelength.

• Proceedings of the Korean Society of Computer Information Conference
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• 2017.07a
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• pp.372-373
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• 2017

본 논문에서는 도래한 4차산업사회 속에서 문화콘텐츠인 캐릭터를 무료 3D모델링 도구를 이용하여 디자인하고 3D 프린팅 기술을 접목하여 개인맞춤형 캐릭터를 제작 및 판매 하고자 하는 사업에 대한 로드맵을 제시해보고자 한다. 이를 위해 첫 단계로서 3D 모델링 도구의 전반적인 특성을 살펴보고 3D 캐릭터 모델링 도구들 중에서 무료로 사용할 수 있고 사용하기 편한 도구들을 정리하여 제시해보고자 한다. 제작하고자 하는 캐릭터의 특성에 맞는 도구를 선택하고 학습하여 성공적인 창업을 할 수 있도록 방향을 제시하고자 한다.

• International Journal of Internet, Broadcasting and Communication
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• v.11 no.3
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• pp.8-19
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• 2019

Since their emergence in 2007, smart phones have advanced up to the point that 5G mobile communication in 2019 started to be commercialized. Accordingly, now it is possible to share 3D modeling files and collaborate by means of a mobile web. As the recently commercialized 5G mobile communication network is so useful in sharing 3D modeling files and collaborating that even large-size geometry files can be transmitted at ultra high speed with ultra low transfer delay. We examines characteristics of major 3D file formats such as STL, OBJ, FBX, and glTF and compares the existing 4G LTE (Long Term Evolution) network with the 5G NR (New Radio) mobile communication network. The loading time and packets of each format were measured depending on the mobile web browser environments. We shows that in comparison with 4G LTE, the loading time of STL and OBJ file formats were reduced as much as 6.55 sec and 9.41 sec, respectively in the 5G NR and Chrome browsers. The glTF file format showed the most efficient performance in all of the 4G/5G mobile communication networks, Chrome, and Edge browsers. In the case of STL and OBJ, the traffic was relatively excessive in 5G NR and Edge browsers. The findings of this study are expected to be utilized to develop a 3D file format that reduces the loading time in a mobile web environment.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.4 s.119
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• pp.358-363
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• 2007

The multi-band and wide-band antenna for a portable broadcasting terminal is proposed. The proposed antenna consists of two radiators with a parallel structure. The antenna has an enough wide impedance bandwidth for the DVB-H(Digital Video Broadcasting-Handheld) service band since two radiators have adjacent resonance frequencies and operates in the DAB(Digital Audio Broadcasting) service band using the third harmonic of the radiator 1. The fabricated antenna has VSWR characteristics of less than 2:1 in the frequency band $470{\sim}740\;MHz$ for DVB-H and $1,450{\sim}1,480\;MHz$ for DAB. The measured peak gain of the antenna is $1.97{\sim}4.10\;dBi$ in the DVB-H band and $1.98{\sim}2.04\;dBi$ in the DAB band.

• ETRI Journal
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• v.34 no.1
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• pp.17-23
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• 2012

This paper analyzes the feasibility of a new 3DTV broadcasting service scenario via Advanced Television Systems Committee Mobile/Handheld (ATSC-M/H). We suggest a dual-channel system in which a left-view image is encoded by MPEG-2 with HD quality and a small-sized right-view image is encoded by AVC. Also, the left view is transmitted through ATSC main channel and the right view is transmitted through ATSC-M/H channel. Although the transport stream formats of two channels are different from each other, we demonstrate that it is possible for the ATSC 2.0 decoder to synchronize the display of the left and right views when both encoders use a common wall clock and time stamp. We also propose a program specific information descriptor which guarantees full compatibility with the conventional 2D HDTV and emerging mobile TV services. Finally, we provide the results of subjective visual quality assessment of the proposed system in support of its 3DTV service quality.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.4
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• pp.23-28
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• 2010

Recently, as the number of people using Smartphones increased, several researches has been launched basing it's subject on this issue. In this circumstance, the fusion of sensor technologies and Smartphone offers a variety of functions. The system introduced in the current paper uses a controller which extracts information about accelerating movements of an user. This information is then sent to the Smartphone through Bluetooth communication. The input method proposed in this paper differs from the existing methods such as touch typing or button input in Smartphones. It rather uses the 3-D acceleration sensor which enables users to control their Smartphone anywhere and anytime without directly touching the device. Furthermore, because it is developed for various applications, it can be applied in many different fields.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.7
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• pp.1428-1436
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• 2012

This paper presents the delta image composition methods using Depth-Image-Based Rendering (DIBR) for 3D stereoscopic broadcasting for the low bandwidth mobile DMB broadcasting system. With DIBR, a left and depth images are transmitted to a mobile device, which restores the right view, whose quality may be poor. This paper describes delta image composition methods for the restoration while minimizing the amount of the transmitted data.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.6
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• pp.99-104
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• 2021

The technology of estimating a movement trajectory using a monocular camera such as a smartphone and composing a surrounding 3D image is key not only in indoor positioning but also in the metaverse service. The most important thing in this technique is to estimate the coordinates of the moving camera center. In this paper, a new algorithm for geometrically estimating the moving distance is proposed. The coordinates of the 3D object point are obtained from the first and second photos, and the movement distance vector is obtained using the matching feature points of the first and third photos. Then, while moving the coordinates of the origin of the third camera, a position where the 3D object point and the feature point of the third picture coincide is obtained. Its possibility and accuracy were verified by applying it to actual continuous image data.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2010.07a
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• pp.164-167
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• 2010

`신호 공간 다이버시티(Signal Space Diversity)'기술은 DVB-T2 표준에 포함된 기술로써, 추가적인 전력이나 대역폭의 희생없이 검파에 있어 성능 이득을 얻을 수 있어 DVB-T2 물리계층 핵심적인 기술 중 하나로 평가받으며, 후속 표준인 DVB-NGH 에도 적용 가능성이 높은 기술이다. 본 논문에서는 '신호 공간 다이버시티' 기술을 MIMO 시스템으로 확장하기 위해서 발생하는 문제점에 대해서 분석한 뒤, 이를 해결하기 위해 제안된 '성분 맞교환(Component-Swapping)' 기술을 현재 논의 중에 있는 DVB-NGH 시스템에 적용하여 주어진 실험 환경에서 2.2~3.0dB 가량의 이득을 가짐을 실험적으로 확인하였다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.1
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• pp.47-52
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• 2008

The visual implementation of 3-dimensional national environment is focused by the requirement and importance in the fields such as, urban planing, telecommunication facility deployment plan, railway construction, construction engineering, spatial city development, safety and disaster prevention engineering. The currently used DEM system based on the 2-D digital maps and contour lines has limitation in implementation in reproducing the 3-D spatial city. Currently, the LiDAR data which combines the laser and GPS skill has been introduced to obtain high resolution accuracy in the altitude measurement in the advanced country. In this paper, we first introduce the LiDAR based researches in advanced foreign countries, then we propose the data generation scheme and an solution algorithm for the optimal management of our 3-D spatial u-City construction. For this purpose, LiDAR based height data transformed to DEM, and the realtime unification of the vector via digital image mapping and raster via exactness evaluation is transformed to make it possible to trace the model of generated 3-dimensional model with long distance for 3D u-city model generation.