• Title, Summary, Keyword: Index Structure

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Index Graph : An IR Index Structure for Dynamic Document Database (인덱스 그래프 : 동적 문서 데이터베이스를 위한 IR 인덱스 구조)

  • 박병권
    • The Journal of Information Systems
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    • v.10 no.1
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    • pp.257-278
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    • 2001
  • An IR(information retrieval) index for dynamic document databases where insertion, deletion, and update of documents happen frequently should be frequently updated. As the conventional structure of IR index is, however, focused on the information retrieval purpose, its structure is inefficient to handle dynamic update of it. In this paper, we propose a new structure for IR Index, we call it Index Graph, which is organized by connecting multiple indexes into a graph structure. By analysis and experiment, we prove the Index Graph is superior to the conventional structure of IR index in the performance of insertion, deletion, and update of documents as well as the performance of information retrieval.

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An Index Structure for Main-memory Storage Systems using The Level Pre-fetching

  • Lee, Seok-Jae;Yoon, Jong-Hyun;Song, Seok-Il;Yoo, Jae-Soo
    • International Journal of Contents
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    • v.3 no.1
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    • pp.19-23
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    • 2007
  • Recently, several main-memory index structures have been proposed to reduce the impact of secondary cache misses. In mainmemory storage systems, secondary cache misses have a substantial effect on the performance of index structures. However, recent studies still stiffer from secondary cache misses when visiting each level of index tree. In this paper, we propose a new index structure that minimizes the total amount of cache miss latency. The proposed index structure prefetched grandchildren of a current node. The basic structure of the proposed index structure is based on that of the CSB+-Tree, which uses the concept of a node group to increase fan-out. However, the insert algorithm of the proposed index structure significantly reduces the cost of a split. The superiority of our algorithm is shown through performance evaluation.

A Study on Parallel Spatial Index Structure (병렬처리 공간자료구조연구)

  • Bang, Kapsan
    • Proceedings of the Korea Information Processing Society Conference
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    • pp.775-776
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    • 2009
  • 공간데이터를 관리하는 공간 index structure는 대부분 순차처리를 위한 구조를 가지고 있다. 많은 응용분야에서 방대한 양의 공간 데이터는 보조기억장치(예: disk)에 저장이 되어 사용이 되고 공간 index structure의 operation은 I/O에 대한 의존도가 크므로, I/O operation의 병렬처리는 공간 index structure의 질의반응시간을 현저하게 줄일 수 있다. 본 논문에서는 PPR-tree라는 병렬형 공간 index structure를 제안한다.

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Estimating the Stand Structure Index Based on Lorenz Curve (Lorenz곡선(曲線)에 근거(根據)한 임분구조지수추정(林分構造指數推定))

  • Lee, Woo-Kyun
    • Journal of Korean Society of Forest Science
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    • v.86 no.2
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    • pp.158-166
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    • 1997
  • This study presents the method to quantify the stand structure diversity or homogeneity. Gadow's dbh differentiation(Durchmesserdifferenzierung) is introduced which quantifies the horizontal stand structure by the ratio of the dbh between subject tree and neighbour trees. And new stand structure diversity index based on Lorenz curve, which is made by ratio of tree number and basal area or volume by dbh class, is presented. The horizontal stand structure index based on Lorenz curve has a value from 0 to 1 as Gadow's index, and approximates to 1 if the stand structure has high diversity. In the comparative analysis for performance, the new stand structure index based on Lorenz curve is considered to compare with the Gadow's index for describing the stand structure.

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An Index Structure for Updating Continuously Moving Objects Efficiently (연속적인 이동 객체의 효과적인 갱신을 위한 색인 구조)

  • Bok Kyoung-Soo;Yoon Ho-Won;Kim Myoung-Ho;Cho Ki-Hyung;Yoo Jae-Soo
    • The KIPS Transactions:PartD
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    • v.13D no.4
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    • pp.477-490
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    • 2006
  • Existing index structures need very much update cost because they repeat delete and insert operations in order to update continuously moving objects. In this paper, we propose a new index structure which reduces the update cost of continuously moving objects. The proposed index structure consists of a space partitioning index structure that stores the location of the moving objects and an auxiliary index structure that directly accesses to their current positions. In order to increase the fanout of the node, it stores not the real partitioning area but kd-tree as the information about the child node of the node. In addition, we don't traverse a whole index structure, but access the leaf nodes directly and accomplish a bottom-up update strategy for efficiently updating the positions of moving objects. We show through the various experiments that our index structure outperforms the existing index structures in terms of insertion, update and retrieval.

An Index Structure based on Space Partitions and Adaptive Bit Allocations for Multi-Dimensional Data (다차원 데이타를 위한 공간 분할 및 적응적 비트 할당 기반 색인 구조)

  • Bok, Kyoung-Soo;Kim, Eun-Jae;Yoo, Jae-Soo
    • Journal of KIISE:Databases
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    • v.32 no.5
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    • pp.509-525
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    • 2005
  • In this paper, we propose the index structure based on a vector approximation for efficiently supporting the similarity search of multi-dimensional data. The proposed index structure splits a region with the space partition method and allocates to the split region dynamic bits according to the distribution of data. Therefore, the index structure splits a region to the unoverlapped regions and can reduce the depth of the tree by storing the much region information of child nodes in a internal node. Our index structure represents the child node more exactly and provide the efficient search by representing the region information of the child node relatively using the region information of the parent node. We show that our proposed index structure is better than the existing index structure in various experiments. Experimental results show that our proposed index structure achieves about $40\%$ performance improvements on search performance over the existing method.

IpCSB+ - tree : An Enhanced Main Memory Index Structure Employing the Level Prefetching Technique (레벨 프리페칭 기법을 이용한 향상된 주기억장치 상주형 색인구조)

  • Hong Hyun-Taek;Kang Tae-Ho;Yoo Jae-Soo
    • Journal of Internet Computing and Services
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    • v.4 no.6
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    • pp.75-86
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    • 2003
  • In main-memory resident index structures, secondary cache misses considerably have an effect on the performance of index structures. Recently, several main-memory resident index structures that consider cache have been proposed to reduce the impact of secondary cache misses. However they still suffer from full secondary cache misses whenever visiting each level of a index tree, In this paper, we propose a new index structure that eliminates cache misses even when visiting each level of index tree. The proposed index structure prefetches the grandchildren of a current node. The basic structure of the proposed index structure is from CSB+-tree that uses the concepts of the node group to increase fan-out. However the insert algorithm of the proposed index structure reduces the cost of a split significantly, Also, we show the superiority of our algorithm through various performance evaluation.

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An Efficient Multidimensional Index Structure for Parallel Environments

  • Bok Koung-Soo;Song Seok-Il;Yoo Jae-Soo
    • International Journal of Contents
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    • v.1 no.1
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    • pp.50-58
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    • 2005
  • Generally, multidimensional data such as image and spatial data require large amount of storage space. There is a limit to store and manage those large amounts of data in single workstation. If we manage the data on parallel computing environment which is being actively researched these days, we can get highly improved performance. In this paper, we propose a parallel multidimensional index structure that exploits the parallelism of the parallel computing environment. The proposed index structure is nP(processor)-nxmD(disk) architecture which is the hybrid type of nP-nD and 1P-nD. Its node structure in-creases fan-out and reduces the height of an index. Also, a range search algorithm that maximizes I/O parallelism is devised, and it is applied to k-nearest neighbor queries. Through various experiments, it is shown that the proposed method outperforms other parallel index structures.

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An Efficient Content-Based High-Dimensional Index Structure for Image Data

  • Lee, Jang-Sun;Yoo, Jae-Soo;Lee, Seok-Hee;Kim, Myung-Joon
    • ETRI Journal
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    • v.22 no.2
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    • pp.32-42
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    • 2000
  • The existing multi-dimensional index structures are not adequate for indexing higher-dimensional data sets. Although conceptually they can be extended to higher dimensionalities, they usually require time and space that grow exponentially with the dimensionality. In this paper, we analyze the existing index structures and derive some requirements of an index structure for content-based image retrieval. We also propose a new structure, for indexing large amount of point data in a high-dimensional space that satisfies the requirements. in order to justify the performance of the proposed structure, we compare the proposed structure with the existing index structures in various environments. We show, through experiments, that our proposed structure outperforms the existing structures in terms of retrieval time and storage overhead.

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An Efficient Index Structure Supporting Structure Queries for Video Documents (비디오 문서의 구조 질의를 위한 효율적 인덱스 구조)

  • Lee, Yong-Kyu
    • The Transactions of the Korea Information Processing Society
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    • v.5 no.5
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    • pp.1109-1118
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    • 1998
  • Recently, much attention has been focused on video databases. Video documents also have a hierarchical logical structure like text documents. By exploiting this structure using structure queries, users can obtain greater benefits than by using only content queries. In order to process structure queries efficiently, an index structure supporting fast video element access must be provided. However, there has been little attention to the index structure for video documents. In this paper, we present a tree-structured video document model and a new inverted index structure for video documents. We evaluate the storage requirement and the disk access time of the scheme and present the analytical results.

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