• The Transactions of the Korea Information Processing Society
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• v.3 no.7
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• pp.1669-1679
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• 1996

In this paper, we address the problem of how to replace huffers in multimedia database systems with time-varying skewed data access. The access pattern in the multimedia database system to support audio-on-demand and video-on-demand services is generally skewed with a few popular objects. In addition the access pattem of the skewed objects has a time-varying property. In such situations, our analysis indicates that conventional LRU(least Recently Used) and LFU(Least Frequently Used) schemes for buffer replacement algorithm(ABRN:Adaptive Buffer Replacement using Neural suited. We propose a new buffer replacement algorithm(ABRN:Adaptive Buffer Replacement using Neural Networks)using a neural network for multimedia database systems with time-varying skewed data access. The major role of our neural network classifies multimedia objects into two classes:a hot set frequently accessed with great popularity and a cold set randomly accessed with low populsrity. For the classification, the inter-arrival time values of sample objects are employed to train the neural network.Our algorithm partitions buffers into two regions to combine the best roperties of LRU and LFU.One region, which contains the 핫셋 objects, is managed by LFU replacement and the other region , which contains the cold set objects , is managed by LRUreplacement.We performed simulation experiments in an actual environment with time-varying skewed data accsee to compare our algorithm to LRU, LFU, and LRU-k which is a variation of LRU. Simulation resuults indicate that our proposed algorthm provides better performance as compared to the other algorithms. Good performance of the neural network-based replacement scheme means that this new approach can be also suited as an alternative to the existing page replacement and prefetching algorithms in virtual memory systems.

• The Journal of the Korea Contents Association
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• v.7 no.5
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• pp.110-117
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• 2007

The recent developments of audio/video technology in the ubiquitous media have resulted in a variety of formal feature such as screen sizes for media and the new viewing environment can alter television viewers' experience of mediated communication. So the concern about formal feature of media itself is increasing in the recent media effects studies. From this point of view, this study is conducted to test the effect of the different monitor size of DMB Phone(2'1"), PMP(4'3") and PC monitor(19') on the viewers' memory and emotion of content by experimental research. The results showed that the effect by monitor size on the view's memory and emotion is significant. And watching moving image on a bigger monitor resulted in better memory of visual message elements contained in the content and more favorable emotion of the content.

• Journal of Korea Multimedia Society
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• v.4 no.5
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• pp.371-376
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• 2001

Since continuous media such as video and audio data are displayed within a certain time constraint, their computation and manipulation should be handled under limited condition. Traditional real-time scheduling algorithms cold be directly applicable, because they are not suitable for multimedia scheduling applications which support many clients at the same time. Rate Regulating Proportional Share Scheduling Algorithm based on the stride scheduler is a scheduling algorithm considered the time constraint of the continuous media. The stride schedulers, which are designed to general tasks, guarantee the fairness of resource allocation and predictability. The key concept of RRPSSA is a rate regulator which prevents tasks from receiving more resource than its share in a given period. But this algorithm loses fairness which is a strong point of the stride schedulers, and does not show graceful degradation of performance under overloaded situation. This paper proposes a new modified algorithm, namely Modified Proportional Share Scheduling Algorithm considering the characteristics of multimedia data such as its continuity and time dependency. Proposed scheduling algorithm shows graceful degradation of performance in overloaded situation and it reduces the scheduling violations up to 70% by maintaining the fair resource allocation. The number of context switching is 8% less than RRPSSA and the overall performance is increased.

• The Transactions of the Korea Information Processing Society
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• v.6 no.4
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• pp.1112-1119
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• 1999

Digital watermarking is to embed imperceptible mark into image, video, audio and text data to prevent the illegal copy of multimedia data, arbitrary modification, and also illegal sales of the copes without agreement of copyright ownership. The DCT(discrete Cosine Transforms) transforms of original image is conducted in this research and these DCT coefficients are expanded by Fourier series expansion algorithm. In order to embed the imperceptible and robust watermark, the Fourier coefficients(lower frequency coefficients) can be calculated using sine and cosine function which have a complete orthogonal basis function, and the watermark is embedded into these coefficients, In the experiment, we can show robustness with respect to image distortion such as JPEG compression, bluring and adding uniform noise. The correlation coefficient are in the range from 0.5467 to 0.9507.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.9A
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• pp.746-753
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• 2003

In this paper, we propose an efficient algorithm for non-streaming synchronized data processing based on ATSC-DASE in terrestrial digital data broadcasting services. Non-streaming synchronized data is encapsulated in DSM-CC sections with PTS(presentation time stamp) values associated with A/V and it is transmitted in a form of MPEG-2 TS(transport stream). At the receiver, the transmitted A/V data are processed by PC based set-top box(STB) in real-time, and the transmitted non-streaming synchronized data is also stored at the STB and is displayed at right time by the proposed algorithm. To verity the proper operation of the proposed algorithm, we make a scenario for non-streaming synchronized data by XML, and finally we are able to display it properly by using declarative application(DA) browser.

• Information and Communications Magazine
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• v.11 no.6
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• pp.37-54
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• 1994

Technical innovation on multimedia data processing brings us new multimedia services. Multimedia services are classified into five groups : TVs, computers, telecommunications, periperals, and softwares. This paper surveys on the services in various aspects and, in particular, computer areas are discussed in detail. To provide the services, major subsystems such as highspeed networks, operating systems, intelligent agent based user interfaces are discussed. In particular, multimedia operating systems are the most actively investigating research area as an infrastructure of multimedia computer systems to provide integrated multimedia services. So, the trends of new multimedia operating systems are analyzed and COSMOS (Collaborative Object Sharing for Multimedia Operating System) multimedia group presentation is discussed. The characteristics, model and abstract data structure of COSMOS is described. The performance analysis of 3 person conference system using audio, video and shared graphic editor on COSMOS shows that taking integrated multimedia operating system approach leads changing of new multimedia service environments.

• Journal of Internet Computing and Services
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• v.3 no.2
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• pp.15-26
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• 2002

Since multimedia data such as video and audio data are displayed within a certain time constraint, their computation and manipulation should be handled under limited condition. Traditional real-time scheduling algorithms could net be directly applicable, because they are not suitable for multimedia scheduling applications which support many clients at the same time. Rate Regulating Proportional Share Scheduling Algorithm is a scheduling algorithm considered the time constraint of the multimedia data. This scheduling algorithm uses a rate regulator which prevents tasks from receiving more resource than its share in a given period. But this algorithm loses fairness, and does not show graceful degradation of performance under overloaded situation, This paper proposes a new modified algorithm. namely Modified Proportional Share Scheduling Algorithm considering the characteristics of multimedia data such as its continuity and time dependency, Proposed scheduling algorithm shows graceful degradation of performance in overloaded situation and the reduction in the number of context switching, Furthermore, a new evaluation method is proposed which can evaluate the flexibility of scheduling algorithm.

• Journal of the Korea Society of Computer and Information
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• v.11 no.2 s.40
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• pp.253-261
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• 2006

In spite of the popularity of P2P technology, a multimedia streaming using the P2P technology has been neglected. The reason for this is that the P2P multimedia streaming has suffered from several inherent problems especially poor bandwidth and unreliable connection among peers. We suggest a Multi-Peer Binding Protocol (MPBP) in this paper that provides a virtual single channel composed of multiple connections to several peers to ease these problems. The protocol enables applications to download data from multiple peers simultaneously, so they can achieve throughput improvement and reliable streaming. For this, the MPBP splits media files into small chunks and provides a mechanism for identifying and transmitting each chunk. Implemented MPBP engine focuses on handling an abrupt disconnection from data sending peers and the evaluation result shows the MPBP is able to handle it gracefully. The MPBP is also desisted to support various media types. To verify this, video and audio applications are implemented using the MPBP engine in this paper.

• The Transactions of the Korea Information Processing Society
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• v.4 no.5
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• pp.1153-1161
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• 1997

In this paper, we propose Teloemedicine system on CBM(Computer Based Multimedia) based collaborative multimedia which supports special medicine and collaborative medicine with DB, face-to-face dffedt.This system is an application developed by SDK (Software Development Kit) of DooRae(Distributed Objected Oriented Multimedia Application Crafting Environment for Collaborative)framework.And this system is devel-Oriented Multimedia Applecation Crafting Environment for Collaborative) framework, And this system is devel-oped on windows 95 and windows NT.The scenario of this system is limited within only hospital(LAN), but it is possibloe to support many applications development in various nerwork(MAN, PSYN, WAN)on DooRae.This system has a smoth interaction by video and audio, multiple session, multiple participation, application sharing, toolbox including ICON and whiteboard.Also this system supports realo or non-real type without con-straint of the and space.

• The Journal of the Korea institute of electronic communication sciences
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• v.5 no.2
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• pp.152-157
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• 2010

The development of computer and internet has introduced various types of media - such as, image, audio, video, and voice - to the traditional text-based information. However, most of the information retrieval systems are based only on text, which results in the absence of ability to use available information. By utilizing the available media, one can improve the performance of search system, which is commonly called content-based retrieval and content-based image retrieval system specifically tries to incorporate the analysis of images into search systems. In this paper, a content-based image retrieval system using HSI color space, ART2 algorithm, and SOM algorithm is introduced. First, images are analyzed in the HSI color space to generate several sets of features describing the images and an SOM algorithm is used to provide candidates of training features to a user. The features that are selected by a user are fed to the training part of a search system, which uses an ART2 algorithm. The proposed system can handle the case in which an image belongs to several groups and showed better performance than other systems.