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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 3, Issue 6 - Dec 2000
Volume 3, Issue 5 - Oct 2000
Volume 3, Issue 4 - Aug 2000
Volume 3, Issue 3 - Jun 2000
Volume 3, Issue 2 - Apr 2000
Volume 3, Issue 1 - Feb 2000
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A Design and Implementation of Intelligent Image Retrieval System using Hybrid Image Metadata
Journal of Korea Multimedia Society, volume 3, issue 3, 2000, Pages 209~223
As the importance and utilization of multimedia data increases, it becomes necessary to represent and manage multimedia data within database systems. In this paper, we designed and implemented an image retrieval system which support efficient management and intelligent retrieval of image data using concept hierarchy and data mining techniques. We stored the image information intelligently in databases using concept hierarchy. To support intelligent retrievals and efficient web services, our system automatically extracts and stores the user information, the user's query information, and the feature data of images. The proposed system integrates user metadata and image metadata to support various retrieval methods on image data.
A New Navigation/Traveling Method in Virtual Environment
Journal of Korea Multimedia Society, volume 3, issue 3, 2000, Pages 224~233
An important feature of virtual reality is the facility for the user to move around a virtual environment in a natural and easily controlled manner, Navigation. Navigation involves changing the perspective of the user in the virtual environment (VE). Natural locomotion methods are able to contribute to a sense of presence and reality. This paper focuses on the navigation method in the virtual environment, one of the major interfaces for the interactivity between human and virtual environments in virtual reality circumstances and worlds. It proposes a new navigation method: Intelligent Cruise-Control Navigation (ICCN), which provides a natural and user-centered navigation method in virtual environment and can improve the reality and the presence. Intelligent Cruise-Control Navigation is composed of three major phases: Constant Velocity Navigation, Collision Detection and Avoidance, and Path Adjustment. The ICCN can reduce the user's fatigue and improve the user's presence and reality in the virtual environment. Through the experimental study it has been determined that the ICCN will be a natural, straightforward, and useful interface in VE.
Data Input/Output Time Reduction Scheme with the Simultaneous Transmission Method for Multi-participants Video Conference System
Journal of Korea Multimedia Society, volume 3, issue 3, 2000, Pages 234~240
In this paper, we propose the method in which a stream of multimedia data simultaneously transfers to the main memory and the multimedia processor from the network interface card using a conventional system bus. The proposed method can reduce the input/output time of multimedia data and improve the data stream in the system bus. Also, we compared the number of system bus accesses, bus cycles and data transmission time to the number of participants between the proposed method and the conventional methods in the multi-party video conference systems. The comparison results of performance anticipate that the number of bus accesses of the proposed method was reduced by 50%, and the total transmission time was reduced by 75% as much as the conventional method regardless of the relation of the participant numbers.
Fuzzy Classifier and Bispectrum for Invariant 2-D Shape Recognition
Journal of Korea Multimedia Society, volume 3, issue 3, 2000, Pages 241~252
In this paper, a translation, rotation and scale invariant system for the recognition of closed 2-D images using the bispectrum of a contour sequence and a weighted fuzzy classifier is derived and compared with the recognition process using one of the competitive neural algorithm, called a LVQ( Loaming Vector Quantization). The bispectrum based on third order cumulants is applied to the contour sequences of an image to extract fifteen feature vectors for each planar image. These bispectral feature vectors, which are invariant to shape translation, rotation and scale transformation, can be used to the represent two-dimensional planar images and are fed into a weighted fuzzy classifier. The experimental processes with eight different shapes of aircraft images are presented to illustrate a relatively high performance of the proposed recognition system.
Performance Improvement of Radial Basis Function Neural Networks Using Adaptive Feature Extraction
Journal of Korea Multimedia Society, volume 3, issue 3, 2000, Pages 253~262
This paper proposes a new RBF neural network that determines the number and the center of hidden neurons based on the adaptive feature extraction for the input data. The principal component analysis is applied for extracting adaptively the features by reducing the dimension of the given input data. It can simultaneously achieve a superior property of both the principal component analysis by mapping input data into set of statistically independent features and the RBF neural networks. The proposed neural networks has been applied to classify the 200 breast cancer databases by 2-class. The simulation results shows that the proposed neural networks has better performances of the learning time and the classification for test data, in comparison with those using the k-means clustering algorithm. And it is affected less than the k-means clustering algorithm by the initial weight setting and the scope of the smoothing factor.
Implementation of Acoustic Echo Canceller with A Post-processor Using A Fixed-Point DSP
Journal of Korea Multimedia Society, volume 3, issue 3, 2000, Pages 263~271
In this paper, an acoustic echo canceller(AEC) is implemented by ADSP-2181. This AEC uses a noise robust adaptive algorithm and a postprocessing method which attenuates residual echo using cross-correlation between estimated error signal and microphone input signal. We propose new postprocessing method that uses two thresholds to prevent signal distortion after postprocessing and to improve the performance of AEC without extra computational burden. Through experiments using a 16 bit fixed-point DSP board (ADSP-2181 EZ-KIT Lite board), it is shown that the noise robust adaptive algorithm performs well in the double-talk situations and the convergence speed is comparable to NLMS. Using the postprocessor, ERLE is improved about 20 dB. As a result, the AEC with a postprocessor shows better performance than conventional ones.
A Joint Bitrate Allocation among Multiple Video Sources
Journal of Korea Multimedia Society, volume 3, issue 3, 2000, Pages 272~279
When the multiple video sources are together transmitted through the channel of fixed bandwidth, the efficiently joint bandwidth allocation is necessary. This paper presents the joint bandwidth allocation method to keep the constant picture duality ratio among the video sources. We first find an approximated model of distortion and bitrate for the multiplexing system of multiple sources. Then we obtain the bitrate for each source to have constant distortion ratio among the sources by using the approximated model parameters for simple implementation. It is shown by simulation that the proposed bandwidth allocation can keep almost constant picture quality ratio among the sources in comparison to an independent bandwidth allocation method.
Design and Evaluation of an Efficient Seamless Communication Technique for Mobile Wireless Networks
Journal of Korea Multimedia Society, volume 3, issue 3, 2000, Pages 280~289
This paper presents an efficient method to provide seamless communication in mobile wireless networks. The goal of seamless communication is to provide disruption free service to a mobile user. A disruption in service could occur due to active handoffs. There are many user applications that do not require a total guarantee for disruption free service but would also not tolerate very frequent disruptions. This paper proposes an extended staggered multicast that provides a probabilistic guarantee for disruption free service. The proposed multicast forecasts the direction and velocity for a mobile host. It is possible that data packets for a mobile host are multicasted to not all neighbor cells but a par\ulcorner of neighbor cells those the mobile host will be handoff potentially on the basis of these information. Therefore, the extended staggered multicast significantly reduces the static network bandwidth usage also provides a probabilistic guarantee for disruption free service.
The Study on the Generation of Verifying Rules for Consistency and Completeness of the Unified Modeling Language Diagrams
Journal of Korea Multimedia Society, volume 3, issue 3, 2000, Pages 290~297
For verifying consistency and completeness of some UML diagrams as a representative of the graphic notations for object-oriented designs, we first give an analysis of some UML diagrams and apply simple ER model to the UML diagrams. Next, we formally define this graphical representation as a set of sets and a set of functions. According to the semantics of these functions, we derive a set of rules to assure the consistency and completeness of this graphical representation. These rules will be included with a CASE tool, which possesses both the diagramming facility and the consistency and completeness checking capability.
A Sequence of the Extreme Vertices ova Moving Regular Polyhedron Using Spherical Voronoi Diagrams
Journal of Korea Multimedia Society, volume 3, issue 3, 2000, Pages 298~308
We present an efficient algorithm for finding the sequence of extreme vortices of a moving regular convex polyhedron of with respect to a fixed plane H.. The algorithm utilizes the spherical Voronoi diagram that results from the outward unit normal vectors nF
's of faces of P. It is well-known that the Voronoi diagram of n sites in the plane can be computed in 0(nlogn) time, and this bound is optimal. However. exploiting the convexity of P, we are able to construct the spherical Voronoi diagram of nF
,'s in O(n) time. Using the spherical Voronoi diagram, we show that an extreme vertex problem can be transformed to a spherical point location problem. The extreme vertex problem can be solved in O(logn) time after O(n) time and space preprocessing. Moreover, the sequence of extreme vertices of a moving regular convex polyhedron with respect to H can be found in (equation omitted) time, where m
s) is the number of edges of a spherical Voronoi region sreg(equation omitted) such that (equation omitted) gives one or more extreme vertices.
A Parallel Loop Scheduling Algorithm on Multiprocessor System Environments
Journal of Korea Multimedia Society, volume 3, issue 3, 2000, Pages 309~319
The purpose of a parallel scheduling under a multiprocessor environment is to carry out the scheduling with the minimum synchronization overhead, and to perform load balance for a parallel application program. The processors calculate the chunk of iteration and are allocated to carry out the parallel iteration. At this time, it frequently accesses mutually exclusive global memory so that there are a lot of scheduling overhead and bottleneck imposed. And also, when the distribution of the parallel iteration in the allocated chunk to the processor is different, the different execution time of each chunk causes the load imbalance and badly affects the capability of the all scheduling. In the paper. we investigate the problems on the conventional algorithms in order to achieve the minimum scheduling overhead and load balance. we then present a new parallel loop scheduling algorithm, considering the locality of the data and processor affinity.
Development of Virtual Parallel Processing System for Flexible Task Allocation on the Web
Journal of Korea Multimedia Society, volume 3, issue 3, 2000, Pages 320~332
Web consists of the grand virtual system which is made of all connected computers network. We can solve the huge problem which requires high quality in cost performance and powerful computing power to use a numerous idle state system on internet as process it parallel. However, we have to consider heterogeneous computing resources, accessibility, and reliability to carry out parallel system on global environment, not network but whole Internet. In this paper, We the WebImg system which has the power of web computing, and show the flexible task allocation strategy in heterogeneous hosts. Also, we evaluate its performance, moreover the proposed task allocation strategy supplies fault tolerance by controlling host situation at any time.