• ETRI Journal
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• v.27 no.5
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• pp.635-638
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• 2005

Spatial audio coding (SAC) is an extremely high compact representation of encoded multi-channel audio material. This paper suggests a multi-channel audio service in the terrestrial digital multimedia broadcasting (T-DMB) system using a novel SAC tool, which is called a virtual source location information (VSLI)-based SAC tool. Intensive experiments are presented to evaluate the validity of the proposed VSLI-based SAC tool, and prototypical systems are also presented to demonstrate the reliability of the proposed multi-channel T-DMB system in real applications.

• Journal of Korea Multimedia Society
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• v.25 no.8
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• pp.983-990
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• 2022

In this paper, we implemented a hierarchical encryption system using two-step phase-shifting digital holography(PSDH) technology based on XOR and scramble operations. The proposed encryption system is a system that authenticates access through the issuance of an encryption key for access to individual laboratories, department offices, and universities. In the encryption process, we proposed a double encryption method using XOR and scramble operation with digital technology and two-step phase-shifting digital holography with optical technology. In the two-step PSDH process, an new method of determining the reference wave intensity without measuring it by using random common object image gererated from digital encryption process was also proposed. In the decryption process, the process is performed in the reverse order of encryption process. And only when the various key information used in the encryption process is correct, the encrypted information can be decrypted, so that the user can access the desired place. That is, there is a feature that can hierarchically control the space that can be accessed according to the type of key issued in the proposed encryption system. Through the computer simulation, the feasibility of the proposed hierarchical encryption system was confirmed.

• Journal of Korea Multimedia Society
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• v.13 no.7
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• pp.1095-1104
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• 2010

This study is to suggest the design generation methodology for the maximization of idea generation ability and to overcome restriction of thinking out of existing idea generation methodology, it has suggested the CGS(Character Generation System) that is a creative idea generation methodology identified and complemented the problem of the existing computerized idea generation(PDS with Proportion) method out of the preceded studies on the creative idea generation methodologies. In addition, this research being extended on the article vol.11,no.11, "CGS System based on Three-Dimensional Character Modeling Ⅰ(Part1: about Non-Digital Process )," on Korea Multimedia Society in November 2008 issue and this study is expected to have effectives as one method for idea generation or creative image generation assistance during the 3D character development process with practical implementation of system, research directions and present the results.

• Journal of Digital Contents Society
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• v.6 no.1
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• pp.79-83
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• 2005

Our Digital Carousel enables user to share media objects through media synchronization mechanism. We implemented the Digital Carousel so that the users participated in collaborative work may refer shared media or error objects as the same view to others. This paper explains the design and implementation of the EC_DXS(Error Control in Digital Carousel System). EC_DCS is a system that is suitable for detecting sharing and recovering software error based on multimedia CSCW(Computer Supportes Cooperated Work). With error sharing system, a group cooperating users can share me. applications. From the perspective of multimedia collaborative environment, an error application becomes another interactive presentation error is shared with participant engaged in a cooperative work.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2006.07a
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• pp.380-380
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• 2006

• 한국HCI학회:학술대회논문집
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• 2007.02a
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• pp.624-629
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• 2007

Digital Multimedia Broadcasting (DMB) is a digital radio transmission system for sending multimedia such as radio, TV, and data casting to mobile devices. Nowadays, DMB specifications are the major standard for digital broadcasting and have been establishing for bidirectional service using MPEG-4 system. But there has been only some simple demonstrated system for this bidirectional services. In this paper, we introduce bidirectional DMB data service system that provides the interaction between the user and DMB server without any additional equipment such as web server. The proposed bidirectional DMB system can capture and send user interaction information and response through the existing DMB transmission channel, finally update the original contents. The action event from the user is the most important thing in developing the bidirectional DMB system. Therefor, capturing the event data from the user is the first step we need to do for the bidirectional DMB service. In this paper, we propose an interaction manager module for the user events. This system will extract the user events and make a plan to update the original scene with the server's reaction information.

• Journal of Digital Contents Society
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• v.3 no.2
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• pp.235-243
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• 2002

This paper explains the design and implementation of the ESA(Error Sharing Agent). ESA is a system that is suitable for detecting, sharing and recovering software error based on multimedia CSCW(Computer Supportes Cooperated Work). This system consists of an ED, ES, and ER. ED detects an error by hooking techniques. ES is an agent which is an error sharing system for distributed multimedia collaboration environment With error sharing system, a group cooperating users can share error applications. From the perspective of multimedia collaborative environment, an error application becomes another interactive presentation error is shared with participants engaged in a cooperative work. We propose how an error application can be treated as 'media' in a multimedia collaborative environment.

• Journal of Digital Contents Society
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• v.5 no.1
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• pp.61-65
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• 2004

This paper presents a method of constructing the embedded systems based on hardware/software co-design approach that was key methodology. The proposed method was important technology enable to implement advanced multimedia systems and digital contents creating that are rapidly growing of the new information technology.

• Journal of Information Processing Systems
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• v.18 no.3
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• pp.402-410
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• 2022

Digital data can be manipulated easily, so information related to the timestamp is important in establishing the reliability of the data. The time values for a certain file can be extracted following the analysis of the filesystem metadata or file internals, and the information can be utilized to organize a timeline for a digital investigation. Suppose the reversal of a timestamp is found on a mobile device during this process. In this case, a more detailed analysis is required due to the possibility of anti-forensic activity, but little previous research has investigated the handling and possible manipulation of timestamps on mobile devices. Therefore, in this study, we determine how time values for multimedia files are handled according to the operating system or filesystem on mobile devices. We also discuss five types of timestamps-file created (C), last modified (M), last accessed (A), digitalized (Di), and filename (FN) of multimedia files, and experimented with their operational features across multiple devices such as smartphones and cameras.

• Journal of Digital Contents Society
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• v.15 no.1
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• pp.39-43
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• 2014

This paper suggested a whiteboard for multimedia collaboration work. We implemented the whiteboard so that the users participated in collaborative work may refer shared media objects as the same view to others. In this paper, we discuss a method for increasing reliability of media data through whiteboard. This paper explains a performance analysis of a media data system running on distributed multimedia environment using the rule-based DEVS modeling and simulation techniques.