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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of Korea Multimedia Society
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Korea Multimedia Society
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Volume & Issues
Volume 8, Issue 12 - Dec 2005
Volume 8, Issue 11 - Nov 2005
Volume 8, Issue 10 - Oct 2005
Volume 8, Issue 9 - Sep 2005
Volume 8, Issue 8 - Aug 2005
Volume 8, Issue 7 - Jul 2005
Volume 8, Issue 6 - Jun 2005
Volume 8, Issue 5 - May 2005
Volume 8, Issue 4 - Apr 2005
Volume 8, Issue 3 - Mar 2005
Volume 8, Issue 2 - Feb 2005
Volume 8, Issue 1 - Jan 2005
Selecting the target year
An Efficient Algorithm for Clustering XML Schemas
Rhim Tae-Woo ; Lee Kyong-Ho ;
Journal of Korea Multimedia Society, volume 8, issue 7, 2005, Pages 857~868
Schema clustering is important as a prerequisite to the integration of XML schemas. This paper presents an efficient method for clustering XML schemas. The proposed method first computes similarities among schemas. The similarity is defined by the size of the common structure between two schemas under the assumption that the schemas with less cost to be integrated are more similar. Specifically, we extract one-to-one matchings between paths with the largest number of corresponding elements. Finally, a hierarchical clustering method is applied to the value of similarity. Experimental results with many XML schemas show that the method has peformed better compared with previous works, resulting in a Precision of
and a rate of clustering of
Access Control for XML Documents Using Extended RBAC
Kim, Jong-Hun ; Ban, Yong-Ho ;
Journal of Korea Multimedia Society, volume 8, issue 7, 2005, Pages 869~881
XML(eXtensible Markup Language) has emerged as a prevalent standard for document representation and exchange on the Internet. XML documents contain information of different sensitivity degrees, so that XML Document must selectively shared by user communities. There is thus the need for models and mechanisms enabling the specification and enforcement of access control policies for XML documents. Mechanisms are also required enabling a secure and selective dissemination of documents to users, according to the authorizations which the users have. In this paper, we give an account of access control model and mechanisms, which XML documents can be securely protected in web environments. We make RBAC Based access Control polices to the problem of secure and selective access of XML documents. The proposed model and mechanism guarantee that the secure use for XML documents through definition of authority for element, attribute, link within XML document as well as XML document.
MPEG-2 AAC Encoder Implementation Using a floating-Point DSP
Kim Seung-Woo ;
Journal of Korea Multimedia Society, volume 8, issue 7, 2005, Pages 882~888
MPEG-2 Advanced Audio Coding (AAC) has already been standardized as a sophisticated next generation technology AAC provides an audio signal that has CD quality at 96-128kbps/stereo. This paper describes a high-quality and efficient software implementation of an MPEG-2 AAC LC Profile encoder. Common scalefactor and noisless coding are accelerated by
, respectively, through the use of TMS320C30 instructions. The implemented encoder uses 7.5kWords of program memory, 18kWords of data ROM and 92kBytes of data RAM, respectively. The results of subjective Qualify test showed that the sound quality achieved at 96kbps/stereo was equivalent to that of MP3 at 128kbps/stereo.
Fast Algorithm Based on Successive Elimination Algorithm for Multi-Reference Motion Estimation
Kim Young-Moon ; Lee Jae-Eun ; Lim Chan ; Kang Hyun-Soo ;
Journal of Korea Multimedia Society, volume 8, issue 7, 2005, Pages 889~897
This paper presents a new fast motion estimation algorithm for multi-reference frames. We first analyze the experimental results of the successive elimination algorithm, which is a fast version of full search algorithm, being applied to Multi-reference frames. Based on the analysis, a new scheme for alleviating its computational burden is introduced. In the proposed method, the motion vector for the immediately previous reference frame is found by applying the successive elimination algorithm, while the motion vector for other reference frames is estimated by extrapolation of the already obtained motion vector. Adaptively restricting the motion search area to the local area centered on the estimated motion vector, the proposed method provides dramatic computational complexity reduction but slight quality degradation. The proposed method is evaluated by experiments for some image sequences.
A Study on Eyelid and Eyelash Localization for Iris Recognition
Kang, Byung-Joon ; Park, Kang-Ryoung ;
Journal of Korea Multimedia Society, volume 8, issue 7, 2005, Pages 898~905
Iris recognition Is that identifies a user based on the unique iris muscle patterns which has the functionalities of dilating or contracting pupil region. Because it is reported that iris recognition is more accurate than other biometries such as face, fingerprint, vein and speaker recognition, iris recognition is widely used in the high security application domain. However, if unnecessary information such as eyelid and eyelash is included in iris region, the error for iris recognition is increased, consequently. In detail, if iris region is used to generate iris code including eyelash and eyelid, the iris codes are also changed and the error rate is increased. To overcome such problem, we propose the method of detecting eyelid by using pyramid searching parabolic deformable template. In addition, we detect the eyelash by using the eyelash mask. Experimental results show that EER(Equal Error Rate) for iris recognition using the proposed algorithm is lessened as much as
compared to that not using it.
Image Retrieval Using Sequential Clustering and Projection Information
Won Hyuk-Joon ; Kim Tae-Sun ;
Journal of Korea Multimedia Society, volume 8, issue 7, 2005, Pages 906~915
In this paper we propose content based image retrieval method using sequential clustering and projection information. Proposed method uses the mean of color in clustered color regions by sequential clustering and the projection information in each clustered color regions, which combines spatial information with color information in images efficiently. The experimental results showed that the proposed method retrieval efficiency improved 11.6 percent over conventional methods. In addition, the proposed method robustly tolerates large changes in appearance and shape caused by changes in viewing positions, camera zooms, etc.
A Study on Facial Region Detection and Compression for Transmission of Mobile Avatar
Choi Jae-Young ; Hwang Seung-Ho ; Yang Young-Kyu ; Whangbo Taeg-Keun ;
Journal of Korea Multimedia Society, volume 8, issue 7, 2005, Pages 916~923
In recent times, mobile phones that play an important role in voice communication have became increasingly exciting due to the ability to transmit multimedia contents. However, user's communication cost and service usage fees for digital context exchange are still prohibitive. In this paper, we consider the task of transmitting a facial image in the context of mobile avatar generation. We present image compression as a useful technique to reduce service usage costs of data exchange in mobile communications. In view of this we propose an image compression algorithm that performs better than existing techniques. The suggested algorithm in this paper uses the location of significant coefficient on the wavelet image by detecting facial region as well as the spatial correlation between decomposed bands by wavelet transformation. The algorithm perform well and archives an efficient compression ratio. The proposed method recognizes location information of significant coefficient in advance, thus it is more suitable than existing general compression methods for mobile avatar generation systems.
An Implementation and Evaluation of Large-Scale Dynamic Hashing Directories
Kim, Shin-Woo ; Lee, Yong-Kyu ;
Journal of Korea Multimedia Society, volume 8, issue 7, 2005, Pages 924~942
Recently, large-scale directories have been developed for LINUX cluster file systems to store and retrieve huge amount of data. One of them, GFS directory, has attracted much attention because it is based on extendible hashing, one of dynamic hashing techniques, to support fast access to files. One distinctive feature of the GFS directory is the flat structure where all the leaf nodes are located at the same level of the tree. Hut one disadvantage of the mode structure is that the height of the mode tree has to be increased to make the tree flat after a byte is inserted to a full tree which cannot accommodate it. Thus, one byte addition makes the height of the whole mode tree grow, and each data block of the new tree needs one more link access than the old one. Another dynamic hashing technique which can be used for directories is linear hashing and a couple of researches have shown that it can get better performance at file access times than extendible hashing. [n this research, we have designed and implemented an extendible hashing directory and a linear hashing directory for large-scale LINUX cluster file systems and have compared performance between them. We have used the semi-flat structure which is known to have better access performance than the flat structure. According to the results of the performance evaluation, the linear hashing directory has shown slightly better performance at file inserts and accesses in most cases, whereas the extendible hashing directory is somewhat better at space utilization.
A Performance Evaluation of Cooperative Proxy Caching for Continuous Media Services in Mobile Environments
Lee Haw-Sei ;
Journal of Korea Multimedia Society, volume 8, issue 7, 2005, Pages 943~952
This paper proposes a user's mobility based cooperative proxy caching policy for effective resource management of continuous media objects in mobile environments. This policy is different from the existing proxy caching policies in terms of how to exploit users' mobility. In other words, existing caching policies work based on the information about objects by referring to users' requests within a specified domain whereas the proposed caching policy runs by utilizing a number of users' requests across several domains. So, the proposed policy is applicable to random requests in mobile environments. Moreover, we also propose a replacement policy based on weights and playback time. To check the efficiency of the proposed caching policy, the proposed replacement policy is run with different size of caching unit: object or segment. The result of performance evaluation tells that segment sizes, ratio of users' mobility and weights are major factors for the efficient operation of the cooperative caching.
Stable Recovery Strategy According to Mobility of Mobile Host
Choi Ca-Hyun ; Hwang Byung-Yeon ;
Journal of Korea Multimedia Society, volume 8, issue 7, 2005, Pages 953~960
The Network can be easily damaged in the mobile computing environment. Mobile Support Station (MSS) which supports the Mobile Host(MH) could also be unstable too. Therefore, when a critical error occurs the repairing cost can be high. For stable repair, the hand-off strategy should be considered to save the continuing message and checkpoint information, and to reduce the cost of network repair. In this paper, we propose the Switching Trickle(ST) strategy which reduces the repairing cost for the MH's mobility. ST strategy changes the way which stores the information in connection with the number of write events(r) that occur from the hands-off strategy. Accumulated cost by increased mobility has been simulated too. From the results of simulation, the proposed strategy has shown more cost effective than the conventional strategy. The proposed strategy also has shown very supportive in saving checkpoint and message log information stably.
An Adaptive Steganography of Color Image Using Bit-Planes and Multichannel Characteristics
Jung Sung-Hwan ; Lee Sin-Joo ;
Journal of Korea Multimedia Society, volume 8, issue 7, 2005, Pages 961~973
In this paper, we proposed an adaptive steganography of color image using bit-planes and multichannel characteristics. Applying fixing threshold, if we insert information into all bit-planes of RGB channel, each channels showed different image quality. Therefore, we first defined the channel weight and the bit-plane weight to solve the fixing threshold problem of BPCS (bit-plane complexity steganography) method. We then proposed a new adaptive threshold method using the bit-plane weight of channels and the bit-plane complexity of cover image to increase insertion capacity adaptively In the experiment, we inserted information into the color images with the same image quality and same insertion capacity, and we analyzed the Insertion capacity and image quality. As a result, the proposed method increased the insertion capacity and improved the image quality than BPCS method.
A Security Architecture for ID-Based Cryptographic Schemes in Ad Hoc Networks
Park Young-Ho ; Rhee Kyung-Hyune ;
Journal of Korea Multimedia Society, volume 8, issue 7, 2005, Pages 974~987
As the ad hoc networks have been received a great deal of attention to not only the military but also the industry applications, some security mechanisms are required for implementing a practical ad hoc application. In this paper, we propose a security architecture in ad hoc networks for the purpose of supporting ID-based public key cryptosystems because of the advantage that ID-based schemes require less complex infrastructure compared with the traditional public key cryptosystems. We assume a trusted key generation center which only issues a private key derived from IDs of every nodes in the system setup phase, and use NIL(Node ID List) and NRL(Node Revocation List) in order to distribute the information about IDs used as public keys in our system. Furthermore, we propose a collaborative status checking mechanism that is performed by nodes themselves not by a central server in ad-hoc network to check the validity of the IDs.
Design and Implementation of the Electronic Payment Protocol for Digital Merchandise
Park Sei-Seung ; Han Jae-Kyun ;
Journal of Korea Multimedia Society, volume 8, issue 7, 2005, Pages 988~999
As the Internet continues to have the commercial trade changed, the method of payment is one of critical components to conduct successful businesses through the internet. An electronic cash has all of the characteristics of a traditional commodity cash and ensures the security for all transactions. Accordingly an internet billing system based on the electronic cash is expected as the secure and efficient payment method for the future electronic commerces. The digital contents such as digital merchandise and services have the characteristic that both the delivery of merchandise and the payment of money can be accomplished on the same network and are helpful to idealize the design of the electronic commerce system. In this paper, Anonymity got to be possible by using a virtual ID in the process of payment, the payment steps were decreased by being processed on the same network, and the efficiency and the security were guaranteed by decreasing the frequency of the coding and communication.
A System for Medical Statistical Analysis Using Guide Maps and Interactive Visualization
Lee Don-Soo ; Choi Soo-Mi ;
Journal of Korea Multimedia Society, volume 8, issue 7, 2005, Pages 1000~1011
This paper presents a system for medical statistical analysis that helps medical professionals analyze clinical data more easily and accurately. It is able to recommend proper methods according to the distribution of sample data, and provides guide maps composed of icons for the understanding of the process of analysis. Besides general statistical analysis, it includes commonly-used statistical methods for medical fields, such as survival analysis and methods for repetitive measurements. The results of analysis are interactively displayed by 3D glyph-based visualization with uncertainty.
Design and Implementation of A Multi-Point Multimedia Conference System Using IP Grouping
Sung Baek-Kyon ; Seong Dong-Su ; Lee Keon-Bae ; Hyun Don-Whan ;
Journal of Korea Multimedia Society, volume 8, issue 7, 2005, Pages 1012~1021
This paper describes the design and implementation of an efficient multi-point multimedia conference system using IP grouping. Existing multi-point multimedia conference systems are difficult for multi-user to perform efficient cooperation due to bandwidth limitation for data transmission of video, audio and documentation. In the case that multi-user uses limited bandwidth, smooth cooperation does not accomplish due to transmission delay for the real-time transmission of image and speech data. A hybrid transfer method which is mixed with distributed and centralized methods is used for smooth cooperation, and the network bandwidth is reduced by forming multi-user conference systems of IP grouping in this paper. Also, adaptive image frame variations are used to solve bottleneck effect according to the number of users. An efficient multi-user conference system is designed to support audio quality.