• IEMEK Journal of Embedded Systems and Applications
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• v.1 no.2
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• pp.90-103
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• 2006

There are many file systems in various operating systems. Those are usually designed for server environments, where the common cases are usually 'multiple active users', 'great many small files' And they assume a big main memory to be used as buffer cache. So the existing file systems are not suitable for resource hungry embedded systems that process multimedia data streams. In this study, we designed and implemented a new file system which efficiently stores and retrieves multimedia data steams. The proposed file system has a very simple disk layout, which guarantees a quick disk initialization and file system recovery. And we introduced a new indexing-scheme, called the time-based indexing scheme, with the file system. With the indexing scheme, the file system maintains the relation between time and the location for all the multimedia streams. The scheme is useful in searching and playing the compressed multimedia streams by locating exact frame position with given time, resulting in reduction of CPU processing and power consumption. The proposed file system and its APIs utilizing the time-based indexing schemes were implemented firstly on a Linux environment, though it is operating system independent. In the performance evaluation on a real DVR system, which measured the execution time of multi-threaded reading and writing, we found the proposed file system is maximum 38.7% faster than EXT2 file system.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.20 no.41
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• pp.189-196
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• 1997

Multimedia systems present information by various media, for example, video, sound, music, animation, movie, etc., in addition to the text which has long been used for conveying the information. But using several media may cause users' confusion and poorly designed user interface often aggravate the situation. Hypermedia systems allow the retrieval and representation of multimedia information using navigation and browsing mechanisms. Typically, there are two major navigation problems in a hypermedia compared to the ordinary user interface: disorientation and cognitive overload. In this study, the multimedia system was studied from the viewpoint of usability. Practical usability evaluation needs cost-effective, low-skill, and low- investment methods. The 'discount usability engineering' method, one of these methods, is based on the use of the following techniques: scenarios, simplified thinking aloud, and heuristic evaluation. The discount usability engineering method was applied to the usability evaluation of multimedia CD-ROM title.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.6B
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• pp.593-600
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• 2002

The reverse link signal power required for multimedia traffic in multipath faded single-code (SC-) and multi-code CDMA (MC-CDMA) systems is investigated. The effect of orthogonality loss among multiple spreading code channels is herein characterized by the orthogonality factor. The required signal power in both the CDMA systems is then analyzed in terms of the relative required signal power ratio of data to voice traffic. The effect of varying system parameters including spreading bandwidth, the of orthogonality factor, and the number of spreading codes are examined. Analytical results show that MC-CDMA users transmitting only a single traffic type require significantly more power than SC-CDMA users with only a single traffic type. On the other hand, MC-CDMA users transmitting multimedia traffic require power levels approximately identical to SC-CDMA users with multimedia traffic. The results can be used in the design of radio resource management (e.g., power allocation) scheme for wireless multimedia services.

• Proceedings of the Korea Association of Information Systems Conference
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• 1996.11a
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• pp.110-123
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• 1996

Misunderstanding of multimedia in the computer industry, the confusion of consumers, and the lack of understanding of technology in the human context provide an impetus for examining and speculating on the future of multimedia. "What can a multimedia technology do ?" is not a sufficient question for consumers until we add "for whom." Both how the relevant technology is likely to develop and how human choices would be made are examined with a focus on historical trend in media technology adoption.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 1996.10a
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• pp.110-123
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• 1996

Misunderstanding of multimedia in the computer industry , the confusion of consumers, and the lack of understanding of technology in the human context provide an impetus for examining and speculating on the future of multimedia. "What can a multimedia technology do?" is not a sufficient question for consumers until we add " for whom" . Both how the relevant technology is likely to develop and how human choices would be made are examined with a focus on historical trend in media technology adoption.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2002.05a
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• pp.3-8
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• 2002

This paper introduces the basic concept of computational modeling of perception processes for multimedia data. Such processes are modeled as hierarchical inter- and intra- relationships amongst information in physical, physiological, psychological and cognitive layers in perception. Based on our framework, this paper gives the algorithms for content-based retrieval for multimedia database systems.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.995-998
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• 2005

A task in imprecise computation consists of mandatory part and optional part. The optional part can be executed partially and the quality of service is measured by the amount of the execution. Many paper showed that multimedia systems are good applications of imprecise computation. It is important to guarantee QoS which is a critical factor in multimedia systems. Previous works didn't consider QoS and processor slack were assigned randomly to tasks. This paper presented a systemic slack assignment method according to QoS levels of tasks. A simulation result showed that our method can be a good choice for multimedia systems with QoS requirement.

• Journal of Advanced Navigation Technology
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• v.12 no.6
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• pp.673-680
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• 2008

Multimedia system security can be categorized into groups such as protection of multimedia asset itself and protection of multimedia systems which can process multimedia asset. Divided consideration for these two factors will not hurt the importance of security management. In this paper, managing practices for keeping security level of multimedia systems are induced and categorized.

• The KIPS Transactions:PartC
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• v.9C no.5
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• pp.757-764
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• 2002

This Paper describes our experiences with the design and implementation of a networked multimedia information management system in an object-oriented framework for distributed multimedia applications, and an integrated QoS-resource negotiation protocol which has been applied to a video server in our networked multimedia infrastructure. The salient features of our framework to support efficient multimedia streaming are explained. Next the paper explores the challenges faced in integrating the proposed QoS negotiation policy into the framework.

• Information Systems Review
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• v.1 no.2
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• pp.73-87
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• 1999