• Journal of Korean Library and Information Science Society
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• v.31 no.2
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• pp.279-302
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• 2000

This study is to develop a new automatic system for the Korean thesaurus browser by which we can automatically control all the processes of searching queries such as, representation, generation, extension and construction of searching strategy and feedback searching. The system in this study is programmed by Delphi 4.0(PASCAL) and consists of database system, automatic indexing, clustering technique, establishing and expressing thesaurus, and automatic information retrieval technique. The results proved by this system are as follows: 1)By using the new automatic thesaurus browser developed by the new algorithm, we can perform information retrieval, automatic indexing, clustering technique, establishing and expressing thesaurus, information retrieval technique, and retrieval feedback. Thus it turns out that even the beginner user can easily access special terms about the field of a specific subject. 2) The thesaurus browser in this paper has such merits as the easiness of establishing, the convenience of using, and the good results of information retrieval in terms of the rate of speed, degree, and regeneration. Thus, it t m out very pragmatic.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.7
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• pp.799-803
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• 2010

The KDB-tree is a traditional indexing scheme for retrieving multidimensional data. Much research for KDB-tree family frequently addresses the low storage utilization and insufficient retrieval performance as their two bottlenecks. The bottlenecks occur due to a number of unnecessary splits caused by data insertion orders and data skewness. In this paper, we propose a novel index structure, called as $KDB_{CS}^+$-tree, to process skewed data efficiently and improve the retrieval performance. The $KDB_{CS}^+$-tree increases the number of fan-outs by exploiting bit-vectors for representing splitting information and pointer elimination. It also improves the storage utilization by representing entries as a hierarchical structure in each internal node.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.5
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• pp.1178-1184
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• 2010

In this paper, a mobile search engine architecture that predicts user's search words and recommends them to users in estimated preference order without having additional user inputs. Information obtained from sensors is first sent to the recommendation engine. The related contents are extracted from the context and history databases and recommending words are selected from the contents. Finally, the words are delivered to the mobile device for suggestion. To evaluate the implemented system response time is measured. A satisfaction survey is also performed for 50 users, and improvement in the proposed system is observed.

• Journal of KIISE:Databases
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• v.31 no.3
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• pp.331-339
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• 2004

XML has got to be a new standard for data representation and exchanging by its many good points, and the core part of many new researches and emerging technologies. However, the self-describing characteristic, which is one of XML's good points, caused the spreading of XML documents with different structures, and so the need of the research for the effective XML-document search has been proposed. This paper is for the analysis of the problem in BitCube, which is a bitmap indexing that shows high performance grounded on its fast retrieval. In addition, to resolve the problem of BitCube, we did design and implement xPlaneb(XML Plane Web) which it a new 3-dimensional bitmap indexing made of linked lists. We propose an effective information retrieval technique by replacing BitCube operations with new ones and reconstructing 3-dimensional array index of BitCube with effective nodes. Performance evaluation shows that the proposed technique is better than BitCube, as the amount of document increases, in terms of memory consumptions and operation speed.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.9
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• pp.889-897
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• 2010

Recently, a cutting-edge large-scale image database system has demanded these attributes: search with alarming speed, performs with high accuracy, archives efficiently and much more. An image identifier (descriptor) is for measuring the similarity of two images which plays an important role in this system. The extraction method of an image identifier can be roughly classified into two methods: a local and global method. In this paper, the proposed image identifier, LFH(Local Feature's Histogram), is obtained by a histogram of robust and distinctive local descriptors (features) constrained by a district sub-division of a local region. Furthermore, LFH has not only the properties of a local and global descriptor, but also can perform calculations at a magnificent clip to determine distance with pinpoint accuracy. Additionally, we suggested a way to extract LFH via GPU (OpenGL and GLSL). In this experiment, we have compared the LFH with SIFT (local method) and EHD (global method) via storage capacity, extraction and retrieval time along with accuracy.

• Proceedings of the Korean Society for Cognitive Science Conference
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• 2000.06a
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• pp.19-25
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• 2000

명사 추출기는 정보검색, 문서분류, 문서요약, 정보추출 등의 분야에서 사용되고 있으며, 정확한 명사 추출과 빠른 색인 속도는 이들 시스템 성능과 밀접한 관계가 있다. 한국어에서 명사를 추출하기 위해서는 형태소 분석이 필요한데, 본 논문에서는 대량의 품사부착된 말뭉치로부터 추출한 분석배제 정보와 후절어를 이용함으로써 형태소 분석을 생략하거나 보다 단순한 처리에 의해 명사를 추출하는 방법을 제안한다. 실험결과에 의하면, 제안된 방법에 의한 명사추출기는 비교적 높은 정확률과 재현율을 나타내며, 빠른 속도를 보였다.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04a
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• pp.70-72
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• 2004

본 논문에서는 Grid 시스템에서 작업을 할당하기 위해서, 가능한 모든 작업 분할 방법을 찾는 기법에 대해 연구 하고자 한다. 즉 다수의 노드를 가진 여러 클러스터 사이에 많은 노드를 필요로 하는 작업을 할당하기 위해 변형된 깊이 우선 탐색 트리를 사용하여 작업 분할 리스트를 찾는 방법을 만들고, 그 알고리즘의 속도 및 효율을 평가하였다. 제안된 알고리즘은 전체 리스트를 검색하는 방법에 비해 속도 측면에서 빠른 효율을 보이는 것을 알 수 있다. 따라서 제안된 알고리즘은 동기화된 작업의 스케쥴링에 사용할 경우 유용할 것으로 생각된다.

• Journal of the Korean Institute of Intelligent Systems
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• v.11 no.1
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• pp.76-81
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• 2001

전자교통신호등은 차량이 교차로에 많을 때에는 교통신호주기를 연장할 수 있고, 교차로에 차량이 적을 경우에는 교통신호주기를 단축할 수 있다. 그러나, 요즈음과 같이 교통체증이 많아서 평균주행속도가 10Km-20Km일 때에는 전자신호등의 기능을 수행할 수 없다. 본 논문에서는 퍼지 규칙을 이용하여 최단경로검색 및 최적 녹색시간 알고리즘을 제안한다. 컴퓨터 모의실험결과 앞 막힘 현상이 발생하는 경우에는 평균 승용차 대기시간 및 평균주행속도를 10%-32% 가량 개선시킬 수 있음을 입증하였다.

• Journal of Broadcast Engineering
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• v.8 no.1
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• pp.91-100
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• 2003

In this paper, to improve the retrieval Performance, an efficient combination of the MPEG-7 visual descriptors, such as the edge histogram descriptor (EHD), the color layout descriptor (CLD), and the homogeneous texture descriptor (HTD), is proposed in the framework of the relevance feedback approach. The EHD represents spatial distribution of edges in local image regions and it is considered as an important feature to represent the content of the image. The CLD specifies spatial distribution of colors and is widely used in image retrieval due to its simplicity and fast operation speed. The HTD describes precise statistical distribution of the image texture. Both the feature vector for the query image and the weighting factors among the combined descriptors are adaptively determined during the relevance feedback. Experimental results show that the proposed method improves the retrieval performance significantly tot natural images.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.5B
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• pp.285-295
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• 2008

Internet routers perform packet forwarding which determines a next hop for each incoming packet using the packet's destination IP address. IP address lookup becomes one of the major challenges because it should be performed in wire-speed for every incoming packet under the circumstance of the advancement in link technologies and the growth of the number of the Internet users. Many binary search algorithms have been proposed for fast IP address lookup. However, tree-based binary search algorithms are usually unbalanced, and they do not provide very good search performance. Even for binary search algorithms providing balanced search, they have drawbacks requiring prefix duplication. In this paper, a new binary search algorithm which provides the balanced binary search and the number of its entries is much less than the number of original prefixes. This is possible because of composing the binary search tree only with disjoint prefixes of the prefix set. Each node has a prefix vector that has the prefix nesting information. The number of memory accesses of the proposed algorithm becomes much less than that of prior binary search algorithms, and hence its performance for IP address lookup is considerably improved.