• The Transactions of the Korea Information Processing Society
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• v.7 no.2S
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• pp.629-637
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• 2000

The content-based information retrieval for a multimedia database uses feature information extracted from the compressed videos. This paper presents an effective method to detect scene changes from compressed videos. Scene changes are detected with DC values of DCT coefficients in MPEG-1 encoded video sequences. Instead of decoding full frames. partial macroblocks of each frame, horizontal and vertical macroblocks, are decoded to detect scene changes. This method detects abrupt scene changes by decoding minimal number of blocks and saves a lot of computation time. The performance of the proposed algorithm is analyzed based on the precision and the recall. The experimental results show the effectiveness in computation time and detection rate to detect scene changes of various MPEG-1 video streams.

• Journal of KIISE:Software and Applications
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• v.27 no.12
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• pp.1211-1218
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• 2000

정보검색 분야에서 시소러스 용어와 용어 사이의 관계를 나타내어, 질의어와 검색될 정보 사이에 존재하는 용어적 차이를 줄이는데 사용될 수 있다. 시소러스를 사용하는 방법 중 진보된 것은 용어 사이의 관계에 가중치를 주어, 소위 스프레딩 엑티베이션 방법을 이용하여 주어진 용어에서 다른 용어들 사이의 유사성을 측정하여 이를 검색에 이용한다. 그러나, 이러한 방법은 가중치를 어떻게 할당하느냐에 따라 그 결과가 달라지는 문제점이 발생한다. 본 논문에서는 시소러스의 가중치를 사용자의 검색된 정보에 대한 적합성 반응에 근거하여 조절할 수 있는 신경망 기반 시소러스를 제안한다. 제안된 시소러스의 타당성을 위하여 프로토타입의 시소러스를 WordNet으로부터 추출하여 실험하였으며, 그 결과로 recall-precision 값이 향상됨을 보였다.

• Proceedings of the Korean Information Science Society Conference
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• 1998.10c
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• pp.150-152
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• 1998

정확한 정보를 검색하기 위해 단일단어를 사용하는 대신에 다중단어를 사용하는 정보검색 시스템에 대한 연구가 활발히 진행되고 있다. 그러나 아직까지 다중단어를 이용한 검색시스템은 그리 많지 않다. 다중단어를 이용한 정보검색시스템의 한 예가 키팩트를 이용한 정보검색 시스템이다. 키팩트란 키워드뿐만 아니라 관련정보를 같이 포함하고 있는 다중단어의 하나다. 키팩트에 기반한 정보검색 시스템은 현재 문서의 색인과정과 질의어의 키팩트 추출과정에서 같은 가중치를 가진 키팩트를 생성한다. 그러나, 하나의 명사구는 그것이 갖는 의미에 따라 각기 다른 다양한 키팩트를 생성하기 때문에, 이들의 결과에 기존의 정보검색 방법을 적용하는 것은 문제가 많다. 따라서 본 논문에서는 색인시에 생성되는 각각의 키팩트에 적절한 가중치를 부여함으로써 보다 정확한 정보검색이 이루어지도록 하는 방법을 제안한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2005.11a
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• pp.513-516
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• 2005

단백질 2DE 이미지 분석의 주요작업은 스팟 매칭에 의한 동일한 종류의 단백질 그룹인 패어링 클래스를 구성하는 것으로서 단백질간의 상호 작용, 질병에 관련한 단백질의 변화 등을 관찰할 수 있다. 하지만 2DE 실험의 여러 가지 문제점으로 인하여 패어링 클래스는 먼지, 공기방울 등 에러를 포함하게 되며 이런 에러들은 왜곡된 분석결과를 초래한다. 따라서 본 논문에서는 동일한 조직에서 같은 종류의 단백질은 발현량이 비슷하다는 특성을 이용하여 패어링 클래스의 개개의 스팟을 참조 스팟 속성으로 나눈 값을 유사도로 정의하고, 스팟의 유사도가 사용자에 의하여 선택되는 필터링 배수에 의한 범위를 벗어날 때 에러 스팟으로 간주하여 제거되는 에러 필터링 기법을 제안한다. 실험에서는 정확도(Precision), 재현율(Recall) 및 조화평균(Harmonic-mean) 값을 사용하여 제안된 필터링 기법의 타당성을 보여준다.

• Journal of Information Processing Systems
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• v.12 no.3
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• pp.502-510
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• 2016

Considering video copy transform diversity, a multi-feature video copy detection algorithm based on a Speeded-Up Robust Features (SURF) local descriptor is proposed in this paper. Video copy coarse detection is done by an ordinal measure (OM) algorithm after the video is preprocessed. If the matching result is greater than the specified threshold, the video copy fine detection is done based on a SURF descriptor and a box filter is used to extract integral video. In order to improve video copy detection speed, the Hessian matrix trace of the SURF descriptor is used to pre-match, and dimension reduction is done to the traditional SURF feature vector for video matching. Our experimental results indicate that video copy detection precision and recall are greatly improved compared with traditional algorithms, and that our proposed multiple features algorithm has good robustness and discrimination accuracy, as it demonstrated that video detection speed was also improved.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.12 no.4
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• pp.270-276
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• 2012

With the increase in amount of data and information available on the web, there have been high demands on personalized information retrieval services to provide context-aware services for the web users. This paper proposes a novel dynamic multi-agent context-awareness user profile construction method based on ontology to incorporate concepts and properties to model the user profile. This method comprehensively considers the frequency and the specific of the concept in one document and its corresponding domain ontology to construct the user profile, based on which, a fuzzy c-means clustering method is adopted to cluster the user's interest domain, and a dynamic update policy is adopted to continuously consider the change of the users' interest. The simulation result shows that along with the gradual perfection of the our user profile, our proposed system is better than traditional semantic based retrieval system in terms of the Recall Ratio and Precision Ratio.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.3
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• pp.275-280
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• 2002

A new algorithm for gradual scene change detection in MPEG based frame sequences is proposed in this paper. The proposed algorithm is based on the fact that most of gradual curves can be characterized by variance distributions of edge information in the frame sequences. Average edge frame sequences are obtained by performing "sober" edge detection. Features are extracted by comparing variances with those of local blocks in the average edge frames. Those features are further processed by the opening operation to obtain smoothing variance curves. The lowest variance in the local frame sequences is chosen as a gradual detection point. Experimental results show that the proposed method provides 85% precision and 86% recall rate fur gradual scene changes.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.12
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• pp.3149-3165
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• 2013

Content based image retrieval is increasingly gaining popularity among image repository systems as images are a big source of digital communication and information sharing. Identification of image content is done through feature extraction which is the key operation for a successful content based image retrieval system. In this paper content based image retrieval system has been developed by adopting a strategy of combining multiple features of shape, color and relevance feedback. Shape is served as a primary operation to identify images whereas color and relevance feedback have been used as supporting features to make the system more efficient and accurate. Shape features are estimated through second derivative, least square polynomial and shapes coding methods. Color is estimated through max-min mean of neighborhood intensities. A new technique has been introduced for relevance feedback without bothering the user.

• Proceedings of the Korean Society for Language and Information Conference
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• 2007.11a
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• pp.422-429
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• 2007

The rapid growth of the online information services causes the problem of information explosion. Automatic text summarization techniques are essential for dealing with this problem. There are different approaches to text summarization and different systems have used one or a combination of them. Considering the wide variety of summarization techniques there should be an evaluation mechanism to assess the process of summarization. The evaluation of automatic summarization is important and challenging, since in general it is difficult to agree on an ideal summary of a text. Currently evaluating summaries is a laborious task that could not be done simply by human so automatic evaluation techniques are appearing to help this matter. In this paper, we will take a look at summarization approaches and examine summarizers' general architecture. The importance of evaluation methods is discussed and the need to find better automatic systems to evaluate summaries is studied.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06c
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• pp.168-171
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• 2011

One important issue in semantic web is identification and selection of domain concepts for domain ontology learning when several hundreds or even thousands of terms are extracted and available from relevant text documents shared among the members of a domain. We present a novel domain concept acquisition and selection approach for ontology learning that uses affinity propagation algorithm, which takes as input semantic and structural similarity between pairs of extracted terms called data points. Real-valued messages are passed between data points (terms) until high quality set of exemplars (concepts) and cluster iteratively emerges. All exemplars will be considered as domain concepts for learning domain ontologies. Our empirical results show that our approach achieves high precision and recall in selection of domain concepts using less number of iterations.