• The KIPS Transactions:PartB
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• v.10B no.6
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• pp.695-704
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• 2003

This paper proposes a new scheduling technique to play multimedia data streams in mobile terminals. The paper explores the characteristics of multimedia data streams , firstly. On basis of these characteristics, selection of specific data stream can be possible as well as transcoding protest. Our approach aims at reducing the early-stage delay time more effectively since it makes possible to select and transcodes some specific streams by employing a selection policy rather than transcoding all streams in the playing process Thus, this paper suggests a stream selection policy for the transcoding based on EPOB (End Point of Over Bandwidth). It aims to lower the required bandwidth of multimedia streams than the network bandwidth level and also to minimize early-stage delay time for multimedia streams, which is to be played in mobile terminals.

• The KIPS Transactions:PartB
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• v.9B no.2
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• pp.191-198
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• 2002

Recently, Usage of multimedia server is rapidly increased with expansion of internet that real-time displaying service for multimedia data, MPEG and etc. For these multimedia real-time applications, it is necessary to use a disk array as a storage system. For providing requested service to much more clients at the same time in a multimedia data storage server, considerable varied strategies in a several parts. But especially it is important feature to various parameters for disk array such as relation of striping block size as a system environment and characteristics of video data. In this paper, we implemented real environment of multimedia server which provides MPEG-1 files and evaluated the suitable storage system architectures by applying synthetically generated workloads in the various parameters for disk array.

• The Transactions of the Korea Information Processing Society
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• v.7 no.2S
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• pp.711-720
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• 2000

BADA-IV/XML is a system designed specifically for managing XML. Documents and is essential to various electronic document applications as a fundamental system. BADA-IV/XML supports all of aspects of data model, querying and manipulation operations for managing XML documents. This paper provides an overview of these aspects of the BADA-IV/XML, as well as defines schema classes for stroing, querying and maintaining hierarchical semantics of multimedia documents and structural semantics of complex documents linked with each other, Also a multimedia document query language is designed and implemented to support essential operations for efficient searching and managing multimedia documents. Finally, some simulation results show the performance of the paged VF(Virtual Fragmentation) model and the search model using element's identifier as compared with a general model.

• Annual Conference of KIPS
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• 2003.05c
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• pp.1627-1630
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• 2003

XML이 인터넷상에서 비즈니스 데이터 교환과 저장의 표준으로 자리 잡아감에 파라 많은 데이터베이스 연구자들이 XML과 관계형 보델 간의 스키마 변환 방법에 관한 연구를 수행하게 되었다. 지금까지 두 모델간의 변환 방법이 국내외에서 발표되고 있으나 이들 연구들에 대한 비교 및 고찰에 대한 체계적인 연구가 부족하였다. 본 논문에서는 XML과 관계형 모델간의 스키마 변환 방법에 관한 국내외 연구들을 분류 정리하여 비교 고찰함으로서 향후 XML 스키마와 관계형 데이터베이스간의 데이터교환 및 저장에 관한 연구의 사전(事前) 연구가 되도록 하였다.

• Annual Conference of KIPS
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• 2013.05a
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• pp.236-239
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• 2013

사람과 휴모노이드 로봇 간의 상호작용에 대한 연구는 로봇 연구의 핵심이다. 본 논문에서는 휴모노이드 로봇인 나오 로봇을 통해 서비스 로봇과 사람 간의 상호작용 방법을 연구한다. 특히 로봇이 사람에게 서비스를 제공함으로써 발생하는 상호작용에 초점을 둔다. 로봇이 서비스를 제공하기 위해서는 모터 프리미티브와 작업을 사전에 정의하는 것이 필요하다. 본 논문에서는 작업을 생성하기 위하여 필요한 모터 프리미티브 데이터를 생성하는 시스템을 제안한다. 본 연구에서 설계한 시스템은 모터 프리미티브를 생성하는 단계까지이며, 향후 연구에서는 작업을 생성하는 하기 위한 기반 시스템으로 활용될 수 있다.

• Annual Conference of KIPS
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• 2010.11a
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• pp.1279-1280
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• 2010

There are some cases when SOAP message, where WS-Security and WS-Policy elements are included, may consist of a sensitive and important data. In these cases, the message is highly recommended to be secured. The question exists of how to quickly identify that SOAP message satisfies security requirement and security level of a SOAP message. In this paper, we propose a technique called Bit-Stream which depends on the importance of SOAP elements to automatically identify the vulnerabilities and risks while offering advice for higher security.

• Annual Conference of KIPS
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• 2000.04a
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• pp.692-697
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• 2000

멀티미디어 개인 휴대 통신(MPCS)에서 다중 클래스호에 대한 효율적인 채널할당은 매우 중요하다고 할 수 있다. 본 논문에서는 Image/Voice/Data 호에 대하여 가변적 보호 채널을 할당하는 새로운 방식을 제안하였다. 이러한 방식은 3차원 상태 천이도로 모델링 되며 보호 채널의 크기를 가변적으로 조절함으로써 보다 융통성있는 서비스를 제공하게 되며, 또한 수학적 분석과 시뮬레이션을 통해 비교분석을 수행하였다.

• Proceedings of the Korea Multimedia Society Conference
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• 2000.11a
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• pp.493-497
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• 2000

Fragile watermarking is a technique far autoentication/integrity of digital data. Unlike robust watermarking, il has to design to be vulnerable against some slight processing to verify the modification of digital data. Feature of fragile watermarking is to identify the modifications of data and to locate some places modification occurred at the same time, so it has to identify slight changes of small range if possible. In this paper, fragile watermarking is proposed that the changes of small range on image can be identified using the watermark sequence with period and the values of low bit planes in an image.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.2
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• pp.929-944
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• 2019

Many critical applications require accurate real-time human action recognition. However, there are many hurdles associated with capturing and pre-processing image data, calculating features, and classification because they consume significant resources for both storage and computation. To circumvent these hurdles, this paper presents a recognition machine learning (ML) based system model which uses reduced data structure features by projecting real 3D skeleton modality on virtual 2D space. The MMU VAAC dataset is used to test the proposed ML model. The results show a high accuracy rate of 97.88% which is only slightly lower than the accuracy when using the original 3D modality-based features but with a 75% reduction ratio from using RGB modality. These results motivate implementing the proposed recognition model on an embedded system platform in the future.

• Journal of Korea Multimedia Society
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• v.18 no.8
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• pp.915-924
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• 2015

With growing popularity of cloud computing services, users can more easily manage massive amount of data by outsourcing them to the cloud, or more efficiently analyse large amount of data by leveraging IT infrastructure provided by the cloud. This, however, brings the security concerns of sensitive data. To provide data security, it is essential to encrypt sensitive data before uploading it to cloud computing services. Although data encryption helps provide data security, it negatively affects the performance of massive data analytics because it forbids the use of index and mathematical operation on encrypted data. Thus, in this paper, we propose a novel algorithm which enables to efficiently process a large amount of encrypted data. In particular, we propose a novel top-k processing algorithm on the massive amount of encrypted data in the cloud computing environments, and verify the performance of the proposed approach with real data experiments.