• Title/Summary/Keyword: Query Index

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PdR-Tree : An Efficient Indexing Technique for the improvement of search performance in High-Dimensional Data (PdR-트리 : 고차원 데이터의 검색 성능 향상을 위한 효율적인 인덱스 기법)

  • Joh, Beom-Seok;Park, Young-Bae
    • The KIPS Transactions:PartD
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    • v.8D no.2
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    • pp.145-153
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    • 2001
  • The Pyramid-Technique is based on mapping n-dimensional space data into one-dimensional data and expressing it as B-tree ; and by solving the problem of search time complexity the pyramid technique also prevents the effect \"phenomenon of dimensional curse\" which is caused by treatment of hypercube range query in n-dimensional data space. The Spherical Pyramid-Technique applies the pyramid method’s space division strategy, uses spherical range query and improves the search performance to make it suitable for similarity search. However, depending on the size of data and change in dimensions, the two above technique demonstrate significantly inferior search performance for data sizes greater than one million and dimensions greater than sixteen. In this paper, we propose a new index-structured PdR-Tree to improve the search performance for high dimensional data such as multimedia data. Test results using simulation data as well as real data demonstrate that PdR-Tree surpasses both the Pyramid-Technique and Spherical Pyramid-Technique in terms of search performance.

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Extended R-Tree with Grid Filter for Efficient Filtering (효율적인 여과를 위한 그리드 필터를 갖는 R-Tree 의 확장)

  • 김재흥
    • Spatial Information Research
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    • v.8 no.1
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    • pp.155-170
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    • 2000
  • When we use R-Tree,a spatial index, to find objects matches some predicate, it often leads to an incorrect result of perform filtering step only with MBR. And , each candidates need to be inspected to conform if it really satisfies with given query, so called, 'refinement step'. In refinement step. we should perform disk I/O and expansive spatial operations which is the cause of increasing retrieval costs. Therefore, to minimize the number of candidate after filtering step, two-phase filtering methods were studied, but there was many problems such as inefficiency of filtering,maintenance of additional informations and reconstruction of data resulted from the loss of original information. So , in this paper, I propose an Extended R-Tree which provides ability to retrieve spatial objects only with some simple logical operations using Grid Table, truth table strong the information about the existence of spatial objects, in second filtering step. Consequently , this Extended R-Tree using Grid Filter has low cost of operation for filtering because of efficient second filtering step, and better filtering efficiency caused by high quality of approximation.

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Two-phase Content-based Image Retrieval Using the Clustering of Feature Vector (특징벡터의 끌러스터링 기법을 통한 2단계 내용기반 이미지검색 시스템)

  • 조정원;최병욱
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.40 no.3
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    • pp.171-180
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    • 2003
  • A content-based image retrieval(CBIR) system builds the image database using low-level features such as color, shape and texture and provides similar images that user wants to retrieve when the retrieval request occurs. What the user is interest in is a response time in consideration of the building time to build the index database and the response time to obtain the retrieval results from the query image. In a content-based image retrieval system, the similarity computing time comparing a query with images in database takes the most time in whole response time. In this paper, we propose the two-phase search method with the clustering technique of feature vector in order to minimize the similarity computing time. Experimental results show that this two-phase search method is 2-times faster than the conventional full-search method using original features of ail images in image database, while maintaining the same retrieval relevance as the conventional full-search method. And the proposed method is more effective as the number of images increases.

A Spatial Hash Strip Join Algorithm for Effective Handling of Skewed Data (편중 데이타의 효율적인 처리를 위한 공간 해쉬 스트립 조인 알고리즘)

  • Shim Young-Bok;Lee Jong-Yun
    • Journal of KIISE:Databases
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    • v.32 no.5
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    • pp.536-546
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    • 2005
  • In this paper, we focus on the filtering step of candidate objects for spatial join operations on the input tables that none of the inputs is indexed. Over the last decade, several spatial Join algorithms for the input tables with index have been extensively studied. Those algorithms show excellent performance over most spatial data, while little research on solving the performance degradation in the presence of skewed data has been attempted. Therefore, we propose a spatial hash strip join(SHSJ) algorithm that can refine the problem of skewed data in the conventional spatial hash Join(SHJ) algorithm. The basic idea is similar to the conventional SHJ algorithm, but the differences are that bucket capacities are not limited while allocating data into buckets and SSSJ algorithm is applied to bucket join operations. Finally, as a result of experiment using Tiger/line data set, the performance of the spatial hash strip join operation was improved over existing SHJ algorithm and SSSJ algorithm.

Vantage Point Metric Index Improvement for Multimedia Databases

  • Chanpisey, Uch;Lee, Sang-Kon Samuel;Lee, In-Hong
    • Proceedings of the Korean Information Science Society Conference
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    • 2011.06c
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    • pp.112-114
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    • 2011
  • On multimedia databases, in order to realize the fast access method, indexing methods for the multidimension data space are used. However, since it is a premise to use the Euclid distance as the distance measure, this method lacks in flexibility. On the other hand, there are metric indexing methods which require only to satisfy distance axiom. Since metric indexing methods can also apply for distance measures other than the Euclid distance, these methods have high flexibility. This paper proposes an improved method of VP-tree which is one of the metric indexing methods. VP-tree follows the node which suits the search range from a route node at searching. And distances between a query and all objects linked from the leaf node which finally arrived are computed, and it investigates whether each object is contained in the search range. However, search speed will become slow if the number of distance calculations in a leaf node increases. Therefore, we paid attention to the candidates selection method using the triangular inequality in a leaf node. As the improved methods, we propose a method to use the nearest neighbor object point for the query as the datum point of the triangular inequality. It becomes possible to make the search range smaller and to cut down the number of times of distance calculation by these improved methods. From evaluation experiments using 10,000 image data, it was found that our proposed method could cut 5%~12% of search time of the traditional method.

An Efficient Video Clip Matching Algorithm Using the Cauchy Function (커쉬함수를 이용한 효율적인 비디오 클립 정합 알고리즘)

  • Kim Sang-Hyul
    • Journal of the Institute of Convergence Signal Processing
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    • v.5 no.4
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    • pp.294-300
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    • 2004
  • According to the development of digital media technologies various algorithms for video clip matching have been proposed to match the video sequences efficiently. A large number of video search methods have focused on frame-wise query, whereas a relatively few algorithms have been presented for video clip matching or video shot matching. In this paper, we propose an efficient algorithm to index the video sequences and to retrieve the sequences for video clip query. To improve the accuracy and performance of video sequence matching, we employ the Cauchy function as a similarity measure between histograms of consecutive frames, which yields a high performance compared with conventional measures. The key frames extracted from segmented video shots can be used not only for video shot clustering but also for video sequence matching or browsing, where the key frame is defined by the frame that is significantly different from the previous frames. Experimental results with color video sequences show that the proposed method yields the high matching performance and accuracy with a low computational load compared with conventional algorithms.

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Sequence Stream Indexing Method using DFT and Bitmap in Sequence Data Warehouse (시퀀스 데이터웨어하우스에서 이산푸리에변환과 비트맵을 이용한 시퀀스 스트림 색인 기법)

  • Son, Dong-Won;Hong, Dong-Kweon
    • Journal of the Korean Institute of Intelligent Systems
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    • v.22 no.2
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    • pp.181-186
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    • 2012
  • Recently there has been many active researches on searching similar sequences from data generated with the passage of time. Those data are classified as time series data or sequence data and have different semantics from scalar data of traditional databases. In this paper similar sequence search retrieves sequences that have a similar trend of value changes. At first we have transformed the original sequences by applying DFT. The converted data are more suitable for trend analysis and they require less number of attributes for sequence comparisons. In addition we have developed a region-based query and we applied bitmap indexes which could show better performance in data warehouse. We have built bitmap indexes with varying number of attributes and we have found the least cost query plans for efficient similar sequence searches.

Highlight based Lyrics Search Considering the Characteristics of Query (사용자 질의어 특징을 반영한 하이라이트 기반 노래 가사 검색)

  • Kim, Kweon Yang
    • Journal of the Korean Institute of Intelligent Systems
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    • v.26 no.4
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    • pp.301-307
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    • 2016
  • This paper proposes a lyric search method to consider the characteristics of the user query. According to the fact that queries for the lyric search are derived from highlight parts of the music, this paper uses the hierarchical agglomerative clustering to find the highlight and proposes a Gaussian weighting to consider the neighbor of the highlight as well as highlight. By setting the mean of a Gaussian weighting at the highlight, this weighting function has higher weights near the highlight and the lower weights far from the highlight. Then, this paper constructs a index of lyrics with the gaussian weighting. According to the experimental results on a data set obtained from 5 real users, the proposed method is proved to be effective.

Query Processing Model Using Two-level Fuzzy Knowledge Base (2단계 퍼지 지식베이스를 이용한 질의 처리 모델)

  • Lee, Ki-Young;Kim, Young-Un
    • Journal of the Korea Society of Computer and Information
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    • v.10 no.4 s.36
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    • pp.1-16
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    • 2005
  • When Web-based special retrieval systems for scientific field extremely restrict the expression of user's information request, the process of the information content analysis and that of the information acquisition become inconsistent. Accordingly, this study suggests the re-ranking retrieval model which reflects the content based similarity between user's inquiry terms and index words by grasping the document knowledge structure. In order to accomplish this, the former constructs a thesaurus and similarity relation matrix to provide the subject analysis mechanism and the latter propose the algorithm which establishes a search model such as query expansion in order to analyze the user's demands. Therefore, the algorithm that this study suggests as retrieval utilizing the information structure of a retrieval system can be content-based retrieval mechanism to establish a 2-step search model for the preservation of recall and improvement of accuracy which was a weak point of the previous fuzzy retrieval model.

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Implementation of Algebra and Data Model based on a Directed Graph for XML (방향 그래프 기반 XML 데이터 모델과 대수 구현)

  • Park, Seong-Hui;Choe, Eun-Seon;Ryu, Geun-Ho
    • The KIPS Transactions:PartD
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    • v.8D no.6
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    • pp.799-812
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    • 2001
  • As XML become more popular for encoding data and exchanging format on the web, recent work on processing XML Document in DBMS has been performed. However, there is no formal data model for XML, and there is lack of research on XML algebra for processing complex XML query and even the mediators have many restrictions. Therefore, this paper proposes formal data model and algebra based on directed edge labeled graph for XML query. To implement algebra, not only algorithms of operation for algebra are presented, but also they are implemented using access method and path index based on RDBMS or ORDBMS. In particular, experiments to show the effectiveness of the implemented algebra are performed on XML documents on EST data which are semistructured data.

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