• Proceedings of the Korea Information Processing Society Conference
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• 2018.05a
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• pp.44-47
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• 2018

시계열 데이터 처리를 위해 방대한 양의 데이터를 스토리지에서 빠르게 읽어와 처리하려는 움직임이 많아지고 있다. 이를 위해 스토리지의 read latency 를 개선하기 위한 여러 기법들이 제안되었지만, 이 기법들은 분산 노드의 스토리지 자원을 충분히 활용하지 못한다는 한계가 있다. 따라서 우리는 시계열 데이터를 실시간으로 처리하기 위해 스토리지에 병렬적으로 접근하여 read latency 를 개선하는 기법을 제안한다. 제안된 기법은 분산 환경에서 스토리지에 병렬적으로 접근하여, 각 노드에서 부분적으로 데이터를 읽어와 전체 데이터를 읽어오는 지연시간을 줄인다. 우리는 제안된 기법을 여러 노드로 구성된 분산 환경에서 구현하였다. 제안된 기법을 적용한 결과, 전체 데이터를 읽어오는 read latency 가 기존 기법보다 28.04% 줄어든 것을 확인하였다.

• Journal of Broadcast Engineering
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• v.11 no.3 s.32
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• pp.363-378
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• 2006

The Digital Multimedia Broadcasting(DMB) system is developed to offer high quality audio-visual multimedia contents to the mobile environment. The system adopts MPEG-4 standard for the main video, audio and other media format. It also adopts the MPEG-4 scene description for interactive multimedia contents. The animated and interactive contents can be actualized by BIFS(Binary Format for Scene), the binary format for scene description that refers to the spatio-temporal specifications and behaviors of the individual objects. As more interactive contents are, the scene description is also needed more high bitrate. However, the bandwidth for allocating meta data such as scene description is restrictive in mobile environment. On one hand, the DMB terminal starts demultiplexing content and decodes individual media by its own decoder. After decoding each media, rendering module presents each media stream according to the scene description. Thus the BIFS stream corresponding to the scene description should be decoded and parsed in advance of presenting media data. With these reason, the transmission delay of BIFS stream causes the delay of whole audio-visual scene presentation although the audio or video streams are encoded in very low bitrate. This paper presents the effective optimization technique for adapting BIFS stream into expected MPEG-2 TS bitrate without any bandwidth waste and avoiding the transmission delay of the initial scene description for interactive DMB contents.

• Journal of Korea Multimedia Society
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• v.10 no.11
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• pp.1367-1383
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• 2007

A sensor network consists of a network of sensors that can perform computation and also communicate with each other through wireless communication. Some important characteristics of sensor networks are that the network should be self administered and the power efficiency should be greatly considered due to the fact that it uses battery power. In sensor networks, when large amounts of various stream data is produced and multiple queries need to be processed simultaneously, the power efficiency should be maximized. This work proposes a technique to create an index on multiple monitoring queries so that the multi-query processing performance could be increased and the memory and power could be efficiently used. The proposed SMILE tree modifies and combines the ideas of spatial indexing techniques such as k-d trees and R+-trees. The k-d tree can divide the dimensions at each level, while the R+-tree improves the R-tree by dividing the space into a hierarchical manner and reduces the overlapping areas. By applying the SMILE tree on multiple queries and using it on stream data in sensor networks, the response time for finding an indexed query takes in some cases 50% of the time taken for a linear search to find the query.

• The Journal of the Korea Contents Association
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• v.4 no.1
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• pp.55-66
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• 2004

Recently, as the personal computers are supplied rapidly, they formed the nucleus of the computer system. But, because of the easiness that anyone uses them to go near easily, it is the fact that the security of personal computer is weakness. So, in the paper, 1 propose the technical method that minimizes the loss and leakage of important data. This paper implemented a crypto system for security of data file on personal computer and assistance storage medium. The way of encryption/decryption is applied by complexity method which mixed Diffie-Hellman key exchange protocol, a typical RC4(Rivest Cipher version 4) algorithm of stream cipher and a typical MD5(Message Digest version 5) of Hash Function. For valuation implemented crypto system, three criteria is presented, which are crypto complexity, processing time and pattern matching. And according to analysis the three criteria the crypto system is verified the security, efficiency and usefulness. The crypto system is programmed with Visual C++ language of Microsoft. And so, as this is software system, we shall have a technical security system at a minimum cost for all personal computer.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.12
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• pp.5042-5048
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• 2010

In ubiquitous environments, many continuous query processing techniques make use of operator network and sharing methods on continuous data stream generated from various sensors. Since similar continuous queries with the location information intensively occur in specific regions, we suggest a new operator sharing method based on grid partition for the spatial continuous query processing for location-based applications. Due to the proposed method shares moving objects by the given grid cell without sharing spatial operators individually, our approach can not only share spatial operators including similar conditions, but also increase the query processing performance and the utilization of memory by reducing the frequency of use of spatial operators.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.16 no.11
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• pp.1027-1036
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• 1991

This paper proposes an implementation of ODIF(Open Document Interchange Format)decoder and PostScript converter. AS ODIF data stream based on IS 8613 is described according to ASN.1 notation it is necessary to decode ODIF data stream to the proper internal structure to PostScript format as proposed in order to make hard copies in good quality using LBP(Laser Beam Printer). Among several kinds of DA(Document Architecture) and DAP(Document Application Profile). PDA(Processable DA) and Core 26(Level 2 DAP) are selected for our study. An ODIF data stream submitted by ICL is used to show the conformance in the level of data stream.

• Journal of the Korea Society of Computer and Information
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• v.12 no.2 s.46
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• pp.111-121
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• 2007

In mobile computing environments, data broadcasting is widely used to resolve the problem of limited power and bandwidth of mobile equipments. However, the previous broadcast scheduling methods can be inefficient in the environment where the user requests change dynamically since they are based on static data requests. Moreover, a high-priority user can wait long for infrequently requested data because they never consider the priority of listeners. In this paper, we propose a new broadcast scheduling method that reflects dynamic changes of user requests using user profiles. It also reflects user priorities to reduce the access time of high-priority users. We evaluate the performance of the proposed method through simulation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.10
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• pp.2164-2170
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• 2011

Rapid surge in date quantity lead to increase in storage demand from corporate. The existing SAN with fiber channel is being changed to IP-based SAN environment due to installment and maintenance cost. But the IP-based network still have some similar security problems as existing TCP/IP network. Also, for the security reasons of storage traffic, data are encrypted, but with the existing system, data larger than 10G can't be handled. To address security and speed issue, this paper proposes to a structure applied to IP SAN environment with Parallel Structure Word-based FSR (PS-WFSR) as hardware.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06b
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• pp.52-54
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• 2006

유비쿼터스와 유무선 기술의 발전으로 최근들어 각 개인과 그를 둘러싼 환경으로부터 지속적으로 많은 데이터를 수집할 수 있게 되었다. 상황인지 기법들을 활용하면, 수집된 데이터께서 각 개인의 경험을 요약할 수 있는데, 요약된 경험 정보는 해당 개인의 기억 회상에 도움을 줄 뿐 아니라, 다른 사람들과의 상호작용을 증대시키는 데도 유용하게 사용된다. 본 논문에서는 모바일 상에서 수집된 특이성 정보를 바탕으로 사용자의 프로필을 고려하여 개인의 일과를 만화의 형태로 표현하는 방법을 제안한다 특이성 정보는 휴대폰 로그로부터 상황인식 기법을 통해 추론된 것으로 사용자의 행동 및 감정 정보를 나타낸다. 추론된 사용자의 행동 및 감정 정보들과 미리 입력된 사용자 프로필을 바탕으로 본 논문에서는 배경과 캐릭 터 만화 이미지들을 의미적 유사도를 사용하여 합성한다. 또한, 생성된 만화 이미지들에서 동적으로 스토리 스트림을 구성하여 만화 내용의 일관성을 유지한다. 제안하는 만화 생성 방법을 평가하기 위하여 특이성 시나리오를 바탕으로 만화를 합성하여 생성된 만화의 다양성과 일관성을 평가하였다.

• The KIPS Transactions:PartC
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• v.9C no.6
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• pp.953-960
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• 2002

Rel-time application programs have constraints which need to be met between media-data. It is client-leading synchronization that is absorbing variable transmission delay time and that is synchronizing by feedback control and palyout control. It is the important factor for playback rate and QoS if the buffer level is normal or not. This paper, The method of maintenance buffer normal state transmits in multimedia server by appling feedback of filtering function. And synchronization method is processing adaptive playout time for smooth presentation without cut-off while media frame is skip. When audio frame which is master media is in upper threshold buffer level we decrease play out time gradually, low threshold buffer level increase it slowly.