• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.89-91
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• 2007

Multimedia service based on interactivity, personalization, multiple channels and community distinguishes IPTV from incumbent TV. But data encoding/decoding time and image frame processing should be considered in digital TV versus analog device. Especially channel zapping time is one of the most important parameters for the service quality of IPTV. This paper proposes the mechanism for decreasing the channel zapping time with multiple decoder and image frame processing. We also implemented the multi-group video community service system using IP multicasting function supporting interactive learning service.

• Journal of Communications and Networks
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• v.8 no.4
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• pp.432-441
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• 2006

As the community antenna television (CATV) networks becomes ubiquitous, instead of constructing an entirely new broadband network infrastructure, it has emerged as one of the rapid and economic technologies to interconnecting heterogeneous network to provide broadband access to subscribers. How to support ubiquitous real-time multimedia applications, especially in a heavy traffic environment, becomes a critical issue in modern CATV networks. In this paper, we propose a time guaranteed and efficient upstream minislots allocation algorithm for supporting quality-of-service (QoS) traffic over data over cable service interface specification (DOCSIS) CATV networks to fulfill the needs of realtime interactive services, such as video telephony, video on demand (VOD), distance learning, and so on. The proposed adaptive fast expansion algorithm and the loading statistics with dynamic swapping algorithm have been shown to perform better than that of the multimedia cable network system (MCNS) DOCSIS.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.2
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• pp.417-426
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• 1996

The end-to-end service clock recovery is a critical issue in providing constandt bit rate service through ATM network. The Synchronous Residual Time Stamp(SRTS) algorithm is used to recovery the source clock using time stamp of transmitter. In thispaper, we propose a Differential Residual Time Stamp (DRTS) transmission mechanism to effectively deliver the timing information of source clock in SRTS algorithm. The RTS transmission method simple in its hardware. From the results of field trial of DS3 rate interactive video communication system through B-ISDN testbed, it can be identified that DRTS method is superior to the RTS method.

• Journal of Broadcast Engineering
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• v.17 no.4
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• pp.695-706
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• 2012

The purpose of this paper is to propose a service system for a digital hologram video, which has not been published yet. This system assumes the existing service frame for 2-dimensional or 3-dimensional image/video, which includes data acquisition, processing, transmission, reception, and reconstruction. This system also includes the function to service the digital hologram at the viewer's view point by tracking the viewer's face. For this function, the image information at the virtual view point corresponding to the viewer's view point is generated to get the corresponding hologram. Here in this paper, only a prototype that includes major functions of it is implemented, which includes camera system for data acquisition, camera calibration and image rectification, depth/intensity image enhancement, intermediate view generation, digital hologram generation, and holographic image reconstruction by both simulation and optical apparatus. The proposed prototype system was implemented and the result showed that it takes about 352ms to generate one frame of digital hologram and reconstruct the image by simulation, or 183ms to reconstruct image by optical apparatus instead of simulation.

• Journal of Korea Multimedia Society
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• v.11 no.4
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• pp.481-491
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• 2008

As the T-DMB (Terrestrial Digital Multimedia Broadcasting) has been actively launched, all the service providers are focusing on finding a new business model using a variety of data services as well as video service. The middleware technology for data broadcasting service, which was presented due to such necessity, known as DMB MATE (Mobile Application Terminal Environment), provides a running environment of the applications and APIs so that the various data applications can support high-level functionalities for the interactive data service. In this paper, in order to effectively provide the data service under restricted channel environment of T-DMB, we introduce a service technology and an interactive data broadcasting system using the DMB MATE, specifically proposing a design method of T-DMB MATE receiver capable of the presented DMB MATE service. Finally, the performance of developed system is confirmed through the T-DMB data broadcasting experiment under a variety of conditions.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.52 no.4
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• pp.252-257
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• 2003

Acrophobia is an abnormal fear of heights. Medications or cognitive-behavior methods have been mainly used as a treatment. Lately the virtual reality technology has been applied to that kind of anxiety disorders. A virtual environment provides patient with stimuli which arouses phobia, and exposing to that environment makes him having ability to over come the fear. Recently, the patient can take diagnose from a medical doctor in distance with the telemedicine system. The hospital and doctors can get the medical data, audio, video, signals in the actual examination room or operating room via a live interactive system. Audio visual and multimedia conference service, online questionary, ECG signal transfer system, update system are needed in this system. Virtual reality simulation system that composed with a position sensor, head mount display, and audio system, is also included in this telemedicine system. In this study, we tried this system to the acrophobia patient in distance.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.1
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• pp.51-59
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• 2011

In this paper, we propose the standardized idea for learning environment of e-Learning 2.0 (originated from Web 2.0 paradigm) to overcome limitations of current passive e-Learning environment. Because current LMS/ LCMS which manages e-learning systems has the limitation of providing various interactive elements when people use video contents to study, it lacks real-timeness and interactivity between teacher-learner and learner-learner in the operation of video contents and has difficulty in measuring accurate progress rate of learners in the process of teaching-learning. Therefore, we designed multimedia contents(both-way learning requisite) to overcome limitations of current e-Learning system and to maximize the effect of learning of learners so that it makes possible to interact between learners and teachers in realtime. For this, this thesis designs the standardized idea based on expanded SCORM standard which is now used for manufacturing LMS/LCMS, and according to ideas we have proposed, it implements e-learning multimedia environment.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.1
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• pp.35-57
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• 2014

Multi-criteria decision making (MCDM) algorithms play an important role in ensuring quality of service in an integrated HetNets (Heterogeneous Networks). The primary objective of this paper is to develop a multi-criteria vertical handoff decision algorithm (VHDA) for best access network selection in an integrated Wireless Local Area Network (WLAN)/Universal Mobile Telecommunications System (UMTS)/Worldwide Interoperability for Microwave Access (WiMAX) system. The proposed design consists of two parts, the first part is the evaluation of an Analytic Hierarchy Process (AHP) to decide the relative weights of handoff decision criteria and the second part computes the final score of the weights to rank network alternatives using Simple Additive Weighting (SAW). SAW ranks the network alternatives in a faster and simpler manner than AHP. The AHP-SAW mathematical model has been designed, evaluated and simulated for streaming video type of traffic. For other traffic type, such as conversational, background and interactive, only simulation results have been discussed and presented in brief. Simulation results reveal that the hierarchical modelling and computing provides optimum solution for access network selection in an integrated environment as obtained results prove to be an acceptable solution to what could be expected in real life scenarios.

• Journal of Digital Convergence
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• v.18 no.10
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• pp.397-402
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• 2020

Hologram can be categorized into analog and digital hologram but there's a clear limitation in expensive equipment and content realization for ordinary people to realize. In addition, it's required to conduct study on hologram contents with interaction added, escaping out of exiting stable format like endlessly repetitive contents or passive view through specific video. Therefore, this article aims to suggest fusion image system, especially focusing on floating hologram among similar holograms. Eight elements of hologram interaction are as follows: height of camera in a three-dimensional space, interval between 3D model, overlapped model, scale, animation, position, color and 3D model change. For the floating hologram, the audience can control by themselves in real time, the popular, active hologram contents-making methodology is suggested by making the best use of fusion image system and making floating hologram easily without using expensive hologram equipment. The image system developed in actual exhibition and feedback should be complemented to develop better hologram image system.

• Journal of Korea Multimedia Society
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• v.22 no.10
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• pp.1208-1214
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• 2019

4th industrial age! 5G-based video content has changed rapidly. How do you view and understand VR/AR/MR/holograms in the age of convergent technology media represented by digital convergence in the 21st century beyond the modern visual system of Descartes? It predicts extension to an interactive visual system. This study proposes a methodology to visualize the Lacanian visual acuity after applying it to the L-System and to understand the visual system of the 21st century.