• Proceedings of the Korean Information Science Society Conference
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• 2003.10b
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• pp.388-390
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• 2003

멀티미디어 시스템의 사용이 일반화되고, 그 영향범위가 넓어짐에 따라 이러한 시스템의 개발과 테스트는 매우 중요한 요소가 된다. 멀티미디어 시스템은 기존의 시스템과 달리 시간-의존적이고 연속적인 미디어를 포함하여 다양한 미디어를 통합한 컨텐츠 기반 실시간 시스템이며, 사용자와의 상호작용과 네트워킹이 중요한 요소라는 점에서 기존의 시스템과 다른 개발주기. 품질 평가 척도를 가지게 된다. 이에 본 논문은 멀티미디어 시스템이 어떻게 구성되어 있으며 그 특성이 무엇인지 분석하고, 이에 기반하여 기존의 시스템과 다른 시스템 개발주기, 품질평가 척도 및 이에 따라 요구되는 테스팅 영역에 대하여 제시하고자 한다.

• Journal of Korea Multimedia Society
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• v.5 no.3
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• pp.316-322
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• 2002

In this paper we consider continuous block allocation scheme of UNIX file system to support real time retrieval service. The proposed block allocation scheme is designed to place real time data at appropriate disk block location in considering the consume-rate that is given with real time data. To effectively determine the disk block location we analyze the relationship between consume-rate and the two variable factors that are the number of continuous blocks and the cylinder distance of logically consecutive data. In traditional UNIX block allocation scheme it is in fact impossible to find continuous free disk blocks in a specific cylinder location. Thus we propose new bitmap-based free block allocation scheme that enables to determine whether a block in specific cylinder location is free state, or not.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.36C no.10
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• pp.75-80
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• 1999

Multimedia synchronization model for distributed, continuous or discrete media that was guaranteed high quality of service is requited in developing multimedia application software. In this paper we have specific object controller which is called dynamic key media that is changed by user event generation. This becomes media whose event occurrence and periods can't be predicted. For event occurrence not only audio but also text and image can be chosen for key media and performs its role. Object controller transfers information for next transition. The proposed model offers high qualify of services by permitting maximum allowed jitter and skew in playout time and verified its effectiveness by simulation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.8
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• pp.1743-1749
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• 2011

The multimedia data for video-on-demand(VOD) service has large, continuous and real time characteristics. The frequent disk I/O operations takes much time and decrease the system performance in multimedia services. Therefore the efficient buffer management is needed in order to reduce the disk accesses to multimedia data. This paper addresses how to increase the buffer hit ratio and the number of users in a multimedia service like VOD by increasing the utility of buffer. This paper also simulated various resource management algorithms and strategies and evaluated, compared and analyzed their performances.

• The KIPS Transactions:PartB
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• v.11B no.6
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• pp.691-700
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• 2004

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 user's requests within a specified domain whereas the proposed caching policy runs by utilizing a number of user's 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 analyze tells what a ratio of user's mobility is are major factors for the efficient operation of the cooperative caching.

• The Transactions of the Korea Information Processing Society
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• v.4 no.5
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• pp.1172-1181
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• 1997

A militimedia data is a data mixed of formatted data like an audio and video. Multimedia data has characteristics that it need large amount of storage,wide network bandwith andreal time responsibolity. Because of these characteristocs, the VOD server and continous media storage server have a disk stripe structure or disk stripe sructure or disk array structure(RAID).In the parallel disk access system,high-speed play-back of continous media using segment interleavung may not ensure Qos pf other cioents because of the concentrated load within some disks. The load concentration of disks is related to both the number of disks in the system and playback rate of contimous media.In this paper. we describe that high-speed playback scheme,which is independent of the number of disk and plyback rate can be achieved by technique of changing the in-teval of access to segnent location.We show the experimental result of this technique in this pater.

• The Transactions of the Korea Information Processing Society
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• v.6 no.12
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• pp.3642-3651
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• 1999

In this paper, we propose a new caching scheme for continuous media data where the buffer allocation unit is divided into two modes : interval and object. All of objects' access patterns are monitored and based on the results of monitoring, a request for an object is decided to cache its data with either interval mode or object mode. The results of our simulation show that our proposed caching scheme is better than the existing caching algorithms such as interval caching where the access patterns of the objects are changed with time.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.04a
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• pp.1474-1477
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• 2011

정보화 사회에 접어 들면서 정보를 판별하는 능력이 중요시 되고 있다. 그러나 정보가 점점 이질적이고 방대해 짐에 따라 사용자의 의도와 목적에 맞는 정보를 빠르고 정확하게 찾아내는 것이 어렵다. 정보검색 서비스를 제공하는 국내외 포털 사이트에서는 랭크 알고리즘을 이용하여 사용자에게 정보를 제공한다. 그러나 사용자의 요구를 충족시키기 위해 랭킹보다 더 중요한 것 정보를 압축시켜 사용자에게 사용자가 원하는 정보만 제공하는 것이다. 따라서 본 논문에서는 도메인을 제한하여 특화된 정보를 제공하며 사용자 위주의 더 특화된 정보를 제공하는 친구추가 기능을 제안한다. 동시에 주 검색 기능으로 사용자가 등록한 태그 링크를 따라 클릭하면서 연속적으로 정보 검색을 할 수 있는 연속정보검색을 제안한다. 그리고 제안한 시스템을 실제 웹 사이트를 구현을 통해 나타낸다. 제안한 시스템은 사용자에게 효율적으로 유용한 정보를 제공하는 기대효과가 있다.

• The KIPS Transactions:PartA
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• v.11A no.7 s.91
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• pp.511-520
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• 2004

A peer-to-peer model is very useful in solving the server link bottleneck problem of a client-server model. In this work, we discuss the problems of distributing multimedia content over peer-to-peer network. We focus on two problems in peer-to-peer media content distribution systems. The first is the transmission scheduling of the media data for a multi-source streaming session. We present a sophisticated scheduling scheme called fixed-length slotted scheduling, which results in minimum buffering delay. The second problem is on the fast distribution of media content in the peer-to-peer system that is self-growing. We propose a mechanism accelerating the speed at which the system's streaming ca-pacity increases, called FAST.

• Journal of the Institute of Convergence Signal Processing
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• v.3 no.2
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• pp.1-7
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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 not 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.