• Journal of Information Display
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• v.11 no.2
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• pp.76-83
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• 2010

This paper presents the multi-user autostereoscopic 3D display system constructed and operated by the authors using the time-multiplexing approach. This prototype has three main advantages over the previous versions developed by the authors: its hardware was simplified as only one optical array is used to create viewing regions in space, a lenticular multiplexing screen is not necessary as images can be produced sequentially on a fast 120Hz LCD with full resolution, and the holographic projector was replaced with a high-frame-rate digital micromirror device (DMD) projector. The whole system in this prototype consists of four major parts: a 120Hz high-frame-rate DMD projector, a 49-element optical array, a 120Hz screen assembly, and a multi-user head tracker. The display images for the left/right eyes are produced alternatively on a 120Hz direct-view LCD and are synchronized with the output of the projector, which acts as a backlight of the LCD. The novel steering optics controlled by the multiuser head tracker system directs the projector output to regions referred to as exit pupils, which are located in the viewers’eyes. The display can be developed in the "hang-on-the-wall"form.

• The Journal of the Korea Contents Association
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• v.9 no.3
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• pp.28-38
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• 2009

Login process uses both ID and password information to authenticate someone and to permit its access privilege on system. However, an attacker can get those ID and password information by using existing packet sniffing or key logger programs. It cause privacy problem as those information can be used as a hacking and network attack on web server and web e-mail system. Therefore, a more secure and advanced authentication mechanism should be required to enhance the authentication process on existing system. In this paper, we propose a multi-factor authentication process by using software form of secure card system combined with existing ID/Password based login system. Proposed mechanism uses a random number generated from the his/her own handset with biometric information. Therefore, we can provide a one-time password function on web login system to authenticate the user using multi-factor form. Proposed scheme provide enhanced authentication function and security because it is a 'multi-factor authentication mechanism' combined with handset and biometric information on web login system.

• Proceedings of the Korea Information Assurance Society Conference
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• 2004.05a
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• pp.97-101
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• 2004

In this study, we designed A multi-tier e-learning system using hybrid multimedia method, The proposal system can provide an interaction and adaptability of a web-based system and high quality multimedia services of an off-line-based system. The proposal system improved quality of a multimedia, a user's convenience, adaptability and an interaction on e-learning system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.8B
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• pp.1348-1356
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• 2000

In this paper, we proposed a trellis coded Multi-Carrier CDMA 16 QAM system with multiple transmit/receive antenna diversity technique, which is simple and suitable for indoor wireless communications. The proposed multiple transmit/receive antenna diversity technique is that the transmitter sends a trellis coded Multi-Carrier CDMA 16 QAM signal from multiple transmitting antennas with intentional time delays, which makes a receiver possible to distinguish and combine the signals from different antennas. In wireless indoor communication system, if we allow the increase of the complexity of the system, it is also possible to achieve additional diversity gain in the performance with the combination of the proposed technique and the conventional receiving antenna diversity. Furthermore, we have found that the proposed trellis coded Multi-Carrier CDMA 16 QAM system, which employs multiple transmit/receive antenna, is less sensitive to the multiple user interference and fading than conventional receiving antenna diversity systems.

• The Journal of the Korea Contents Association
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• v.13 no.7
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• pp.1-8
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• 2013

As yet the use of 3D projection mapping facade has been limited to advertising and performance in the outside. And interactive elements are lacking. In this paper, propose a interaction system which control of projection mapping facade for multi-audience participation using smart devices. The system can be interaction for the multi-façade. And single or multiple can participate in the game. A user test based on the result confirmed an effectiveness of the proposed method. This research showed a practical method in which interaction of projection facade system can be used to user devices. The results of this study can be used as a base module for projection facade interaction system. In addition, It can be utilized for converged content development such as performances, games, education and various applications services.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.791-793
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• 2015

Recently, UCC (User Created Contents) and VoD (Video on Demand), and multimedia content are growing, IP-TV, Smart TV, OHTV (Open Hybrid TV) various services such as multi platform (Multi-platform) environment, services and QoS issues. To solve this problem, the network efficiently, and improve the quality of content is necessary for the system. In this paper, the network of channels State and transmission of multimedia data based on dynamic resource usage, TCP and UDP, Adaptive dual-streaming system used for design and analysis. In addition, the existing TCP and UDP streaming system using a single protocol for analysis and verification of the effectiveness of the difference between and. This is a disaster, and medical/first aid system will be utilized in the field of feed, are ubiquitous.

• Journal of Broadcast Engineering
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• v.24 no.5
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• pp.743-754
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• 2019

System for three degrees of freedom plus (3DoF+) and 6DoF requires multi-view high resolution 360 video transmission to provide user viewport adaptive 360 video streaming. In this paper, we implement 3DoF+ 360 video compression system which removes the redundancy between multi-view videos and merges the residual into one video to provide high quality 360 video corresponding to an user's head movement efficiently. Implementations about 3D warping based redundancy removal method between 3DoF+ 360 videos and residual extraction and merger are explained in this paper. With the proposed system, 20.14% of BD-rate reduction in maximum is shown compared to traditional high-efficiency video coding (HEVC) based system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.168-171
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• 2003

교환시스템에서 핵심중 하나가 호 제어이다. 호 제어중 다중 가입자의 동시 통화를 설정하기 위한 복수 호 제어가 필요하다. 단말기와 단말기 간의 호를 교환기 내에서 처리함으로써 복수의 단말기들의 통신을 보다 효율적으로 제어가 가능한 교환시스템을 설계하였다. 본 논문에서는 단말의 CRV(Call Refrence Value)의 값을 교환기에서 설정하고 해지함으로써 단말기들의 변화를 모두 관리 할 수 있다.

• Proceedings of the Korea Multimedia Society Conference
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• 2003.05b
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• pp.171-174
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• 2003

다자간 채팅은 인터넷 기반에서 진보적인 발전을 한 분야이고, 네트워크 게임과 같은 어플리케이션 제작에 있어 필수적인 기술이다. 본 논문에서는 자바 기술을 이용하여 one-tier, two-tier 구조가 가진 불편한 유지보수, 데이터 은닉의 문제점을 해결하기 위하여 multi-tier architecture로 아바타를 사용하여 다자간 채팅시스템을 구현하였다. 또한 채팅에서 흥미를 유발하기 위한 캐릭터 전송기술, 다양한 문자를 보내기 위한 문자 포맷 기술을 구현하였다.

• Journal of Navigation and Port Research
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• v.35 no.9
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• pp.735-740
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• 2011

It is necessary to develop the one stop system in order to protect our marine environment rapidly from oil spill accident. The purpose of this study is to develop real time database for oil spill prediction modeling and implement real time prediction modelling with ESI and server-client GIS based user interface. The existing oil spill prediction model cannot provide one stop information system for public and government who should protect sea from oil spill accident. The development of multi user based information system permits integrated handling of real time meteorological data from external ftp. A server-client GIS based model is integrated on the basis of real time database and ESI map to provide the result of the oil spill prediction model. End users can access through the client interface and request analysis such as oil spill prediction and GIS functions on the network as their own purpose.