• Journal of Korea Multimedia Society
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• v.7 no.10
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• pp.1485-1495
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• 2004

We propose the representation of a improved dynamic object-oriented program dependence graph so as to process the slicing of object-oriented programs that is composed of related programs in order to process certain jobs. We also propose an efficient slicing algorithm using the relations of relative tables in order to compute dynamic slices of object-oriented programs. We programmed the algorithm by using fortran and Visual C++. The procedure that computes the dynamic object-oriented program slices using the improved dynamic object-oriented program dependence graph(IDOPDC) is divided into four steps. Consequently, the efficiency of the proposed improved dynamic object-oriented program dependence graph(IDOPDG) technique is also compared with the dependence graph techniques discussed previously. As a result, this certifies that an improved dynamic object-oriented program dependence graph is more efficient in comparison with the traditional dynamic object-oriented program dependence graph(DOPDG).

• Journal of Korea Multimedia Society
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• v.15 no.4
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• pp.485-491
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• 2012

This paper proposes 'Coding Unit Tree' based on quadtree efficiently with motion vector to represent splitting information of a Coding Unit (CU) in HEVC. The new international video coding, High Efficiency Video Coding (HEVC), adopts various techniques and new unit concept: CU, Prediction Unit (PU), and Transform Unit (TU). The basic coding unit, CU is larger than macroblock of H.264/AVC and it splits to process image-based quadtree with a hierarchical structure. However, in case that there are complex motions in CU, the more signaling bits with motion information need to be transmitted. This structure provides a flexibility and a base for a optimization, but there are overhead about splitting information. This paper analyzes those signals and proposes a new algorithm which removes those redundancy. The proposed algorithm utilizes a type code, a dominant value, and residue values at a node in quadtree to remove the addition bits. Type code represents a structure of an image tree and the two values represent a node value. The results show that the proposed algorithm gains 13.6% bit-rate reduction over the HM-1.0.

• Journal of Korea Multimedia Society
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• v.12 no.5
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• pp.677-687
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• 2009

Despite the fact that the mobile environment has favorable conditions for using data contents, it is not easy to implement enhanced data services for mobile broadcasting based on MPEG-4 BIFS. With a structure inherited from VRML, BIFS targets different types of content with a development approach that is not very compatible with broadcasting contents. Furthermore, it is not easy to implement BIFS because the standard is too complicated for the mobile broadcasting environment. Accordingly, this study proposes an enhanced mobile TV contents model that provides interactive 3D objects and GUI for the viewers to interact with the broadcasting contents. By applying the model to the DMB environment, this study suggests a direction for future developments of mobile broadcasting contents. In order to represent 3D graphics on mobile TV, we analyzed MPEG-BIFS 3D nodes and composed a subset of VRML profile, and defined new nodes that can efficiently represent GUI at the content development level. If this study helps facilitate expression of 3D graphics and interactions in data contents composition, enhanced efficiency of contents development is expected to promote the development of various contents suitable for the mobile broadcasting environment.

• Journal of Korea Multimedia Society
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• v.4 no.4
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• pp.316-323
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• 2001

Gamut mapping is a technique that acts on cross-media color reproduction to transform a color between devices for the purpose of enhancing the appearance or preserving the appearance of an image. Gamut mapping essentially produces color conversion error which depends on the gamut mapping method, source and destination devices, and sample points for gamut modeling. For color space conversion between monitor colors and printer colors, empirical representation using sample measurements is currently widely utilized. Color samples are uniformly selected in the device space such as CMY or RGB, represented as color patches, and then measured. However, in the case of printer, these color samples are not evenly distributed inside the printer gamut and the color conversion error is increased. Accordingly, this paper introduces a equally distributed color sampling method in CIELAB space, a device- independent color space, to reduce color conversion error, and the performance is analyzed via color space conversion experiments using three-dimensional interpolation.

• Journal of Korea Multimedia Society
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• v.8 no.11
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• pp.1520-1530
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• 2005

As XML is recognized as a prevalent standard for document representation and exchange in the Internet, the need for security of XML becomes very important issue. Until now researches on XML security have been focused on confidentiality or integrity like encryption and digital signature technology. But, as XML data becomes more massive and complicated, it requires managerial security that decided access permit or deny by the authority oi user who is using the XML data. Thus it requires models and mechanisms enabling the specification and enforcement of access control policies for XML documents. In this paper, we suggest the new access control model and mechanism that separate XML documents by access level, assign roles to each user by applying Role Based Access Control (RBAC) and perform access control to specific documents by encrypting each section with roles. The method, we suggested, has an advantage that it does not need to update the whole keys used in encryption process by updating only the relations between appropriate secure layers.

• Journal of the Korean Society for Library and Information Science
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• v.50 no.3
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• pp.361-381
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• 2016

This study proposed two topical relevance models, simple and complex models, using EEG/ERP techniques. In the simple model regarding simple search tasks, N300 and P3b components are used. The N300 is specific to the semantic processing of pictures and the P3b reflects mechanisms involved in the decision about whether an external stimulus matches or does not match an internal representation of a specific category. In the complex model regarding complex search tasks, on the other hand, N400 and P600 components are used. The N400 reflects activation of an amodel system that integrates both image-based and conceptual representations into a context, whereas the P600 is related to complex cognitive processes. Our research results can be used as a source to design an EEG-based interactive multimedia system.

• Journal of Korea Multimedia Society
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• v.6 no.6
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• pp.1088-1099
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• 2003

The syntax-directed translation using semantic actions is frequently used in construction of compiler for text programming languages. it is very useful for the language designers to develop compiler back-end using a syntax structure of a source programming language. Due to the lack of the integrated representation method for a parse tree node and modeling method of syntax structures, it is very hard to construct compiler using syntax-directed translation in visual languages. In this Paper, we propose a visual language compiler generation method for constructing a visual languages compiler automatically, using syntax-directed translation. Our method uses the Picture Layout Grammar as a underlying grammar formalism. This grammar allows our approach to generate parser efficiently u sing And-Or-Waiting Graph and encapsulating syntax definition as one unit. Unlike other systems, we suggest separating the specification and the generation of semantic actions. Because of this, it provides a very efficient method for modification.

• Journal of Korea Multimedia Society
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• v.10 no.3
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• pp.381-390
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• 2007

3D object contents are used for various applications in the Web virtual space, where the main concerns are to navigate the 3D virtual space and visualize 3D objects. The techniques to manipulate 3D objects like disassembling and assembling and to record the manipulation process are the very first step. Until now, we can record only the result of 3D object manipulation. Thus, we have tried to study the representation technique to record meaningfully and replay the manipulation process of 3D structured objects. We analyzed the structures and their relations between components to construct 3D objects that are described in XML or VRML. Compared to the previous method, we studied a XML based annotation technique to record and store selectively by user. This technique makes 3D structured objects be used in the various applications by the selective recording and also selective replaying.

• Journal of Korea Game Society
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• v.10 no.1
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• pp.135-146
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• 2010

The development of image technologies in such area as broadcasting and movies has recently increased our attention to 3D stereoscopic images. In addition, the development of stereoscopic image representation technologies in 3D contents becomes more active over time due to the representational limitations of 2D images. Without limitation to the above-mentioned area, stereoscopic image technologies have been developed and studied so that they can be widely accessed in diverse areas including medical services and education. Due to the refined production, however, required to represent a three dimensional effects and the fatigue caused by the perception of a three dimensional effects, the stereoscopic image technologies are not combined into real time systems such as games where environments change unforeseeably. In this study we design a technique to adjust the depth scaling that will enable efficient management of a three dimensional effects and to relieve fatigue through automatic view point interval adjustment in accordance with situations based on the geometrical structure of the DirectX SDK graphic pipeline. Through this, we would like to suggest a new alternative idea to activate the production of games combined with stereoscopic image technologies.

• Journal of the Korea Society of Computer and Information
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• v.10 no.1 s.33
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• pp.73-84
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• 2005

An increasing in quantity of multimedia data brought a new problem that expected data should be retrieved fast and exactly. The adequate representation is a key element for the efficient retrieval For this reason, the MPEG-7 standard was established for description of multimedia contents in 2001. Recently, the new metadata were developed to represent characteristics of movie information resources by Korea Federation of Film Archives. In this paper. we designed and implemented a movie information retrieval system. This system used XML schema to accept movie information metada. This system offers a keyword retrieval using high-level metadata based on movie information and similarity retrieval using low-level metadata based on MPEG-7. As a result, that ill be Possible more efficient movie information interchange . movie information metadata reuse and fast retrieve.