• Journal of Korea Multimedia Society
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• v.8 no.12
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• pp.1649-1657
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• 2005

In this paper, a fast implementation of JPEG is discussed and its application to multimedia service is presented for mobile wireless internet. A fast JPEG player is developed based on several fast algorithms for mobile handset. In the color transformation, RCT is adopted instead of ICT for JPEG source. For the most time-consuming DCT part, the binDCT can reduce the decoding time. In upsampling and RGB conversion, the transformation from YCbCr to RGB 16 bit is made at one time. In some parts, assembly language is applied for high-speed. Also, an implementation of multimedia in mobile handset is described using MJPEG (Motion JPEG) and QCELP(Qualcomm Code Excited Linear Prediction Coding). MJPEG and QCELP are used for video and sound, which are synchronized in handset. For the play of MJPEG, the decoder is implemented as a S/W upon the MSM 5500 baseband chip using the fast JPEG decoder. For the play of QCELP, the embedded QCELP player in handset is used. The implemented multimedia player has a fast speed preserving the image quality.

• Journal of Korea Multimedia Society
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• v.5 no.1
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• pp.47-56
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• 2002

Previous buffer cache schemes for multimedia storage systems only exploited the sequential references of multimedia files and didn't consider looping references. However, in some video applications like foreign language learning, users mark the scene as loop area and then application automatically playbacks the scene several times. In this paper, we propose a new buffer replacement scheme, called HBM(Hybrid Buffer Management), for multimedia storage systems that have both sequential and looping references. Proposed scheme assumes that application layer informs reference pattern of files to file system. Then HBM applies an appropriate replacement policy to each file. Our simulation experiments show that HBM outperforms previous buffer cache schemes such as DISTANCE and LRU.

• Proceedings of the Korea Database Society Conference
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• 1997.10a
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• pp.215-269
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• 1997

Outline $\textbullet$ Introduction $\textbullet$ Multimedia - Types of Data - Motivation - Key issue - Hardware Products - Application Areas $\textbullet$ Agents - Rationale for Agents - Sedentary vs. Mobile - Functional Categories - Application Areas $\textbullet$ Data Mining - 2-D Framework for Data Mining Tools - Classification of Tool - Application Areas - Learning Methodologies ＊ Case Based Reasoning ＊ Neural Networks ＊ Statistical Learning： Orthogonal Arrays ＊ Multi-strategy Learning $\textbullet$ Case Study - Finbot $\textbullet$ Conclusion

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2006.11a
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• pp.91-94
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• 2006

Digital Multimedia Broadcasting (DMB) Multimedia Application Format (MAF) [3] specify how to combine the variety of DMB contents with associated information for a presentation in a well-defined format that facilitates interchange, management, editing, and presentation of the DMB contents. The current metadtata specification for DMB MAF [3] is based on TV-Anytime metadata tools. In this paper, we overview the general application scenarios of DMB MAF and then explore the TV-Anytime metadata tools and usage examples proposed for DMB MAF.

• Journal of Multimedia Information System
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• v.8 no.2
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• pp.131-142
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• 2021

This paper traces the process of constructing a new one-dimensional chaotic map, and will provide a simple application in color image encryption. The use of Sarkovskii's theorem will make it possible to determine the existence of chaos and restrict all conditions to ensure the existence of this new sequence. In addition, the sensitivity to initial conditions will be proved by Lyapunov's index value. Similarly, the performance of this new chaotic map will be illustrated graphically and compared with other chaotic maps most commonly used in cryptography. Finally, a humble color image encryption application will show the power of this new chaotic map.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.13-16
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• 1996

Based on the technical innovation of the recent communication system technologies, systems are linked by the worldwide network. We introduce some examples of the multimedia network systems. Especially, we introduce our recent attempt to realize the multimedia tele-surgery system using high speed optical fiber network. At first, we shows the technical problems of the multimedia tele-surgery. We applied this idea to the intravascular neurosurgery. System configuration for the prototype experiments and experimental results are shown.

• Proceedings of the IEEK Conference
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• 2003.07d
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• pp.1677-1680
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• 2003

In this paper, we propose the multimedia tutoring system that provides multimedia learning contents for english Loaming on mobile environment. In order to design and implement the system, we have developed mobile multimedia contents from contents modeling based on the types of item, but also mobile interface to provide learning contents for learners effectively under limitation of mobile environment. The contents server in this system creates multimedia learning contents as XML document for each learner and provides those to learners through mobile interface using Wireless Application Protocol at anytime and anyplace.

• 한국정보통신설비학회:학술대회논문집
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• 2003.08a
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• pp.223-225
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• 2003

Session Initiation Protocol(이하 SIP)은 H.323 network에서 제기된 문제점을 해결하고 다양한 multimedia service를 제공하기위해 IETF에서 정의된 protocol로서, 3GPP의 IP Multimedia Subsystem(이하 IMS)의 기반 protocol로 채택되었다. IMS는 multimedia service를 제공하기 위한 infrastructure로서 CSCF, HSS, MRF, MGCF, IM-GW등 기능적으로 분리된 여러 entity로 구성되며, 향후 추가될 다양한 부가 service에 유연하게 대처할 수 있는 Application Server(이하 AS) mechanism을 포함하고 있다. 현재 AS mechanism을 이용하여 3GPP규격 상에 정의된 대표적 서비스는 presence service이며, presence service network은 presence server, presence agent, presence proxy, watcher등으로 구성된다. 마지막으로 상기에 언급한 규격을 바탕으로 실제 구축된 Instant messaging/presence service network을 제시한다. (본문 참조)

• Journal of Korea Multimedia Society
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• v.13 no.11
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• pp.1677-1686
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• 2010

Application contents verifications and operations are essential for using a secure smart phone environment. In the existing smartphone environment, application verification was performed only in the application company and users has direct management application. However these application verification and management practices have been caused by a variety of security vulnerabilities. Therefore, we will analyze the security vulnerabilities in the existing methods and then we propose an application contents management of smart phone using pre-qualification method.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.86-88
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• 2004

As the rapid incensement of the number of internet users has occurred recently, many multimedia application services have been emerging. To improve quality of service, traffic can be suggested to be classified with priority in EPON(Ethernet Passive Optical Network), which is supporting the multimedia application services. In this paper, multimedia application services treat bandwidth classifying device in serving both delay sensitive traffic for real-time audio, video and voice data such as VoIP(Voice over Internet Protocol), and nonreal-time traffic such as BE(Best Effort). With looking through existing mechanisms, new mechanism to improve the quality will be suggested. The delay performances and packet losses of traffic achieved by supporting bandwidth allocation of upstream traffic in suggested mechanism will be analyzed with simulation.