• Title/Summary/Keyword: Spatial locality

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SLAM : An Efficient Buffer Management Strategy using Spatial Locality of Spatial Data (SLAM : 공간 데이타의 공간적 근접성을 이용한 효율적인 버퍼관리기법)

  • An, Jae-Yong;Min, Jun-Gi;Jeong, Jin-Wan
    • Journal of KIISE:Databases
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    • v.29 no.5
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    • pp.393-403
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    • 2002
  • One of the major issues of DBMS is the buffer management. Because fetching data from the database disk is costly, the number of disk I/O's must be minimized in order to improve the DBMS performance. Although there have been many buffer management strategies to minimize the disk I/O, those strategies usually focused on just the temporal locality. Since there are the spatial locality as well as the temporal locality in the spatial database, strategies using only the temporal locality cannot achieve the optimal performance in the spatial database. In this paper, we propose a new buffer management strategy, the Spatial Locality Area Measure(SLAM) strategy, that considers not only the temporal locality but also the spatial locality. The SLAM buffer management strategy consists of two core structures, the SLM-tree and the M-LRU. We show the efficiency of the proposed strategy through experiments over various buffer sizes and reference frequencies.

An Efficient Buffer Management Technique Using Spatial and Temporal Locality (공간 시간 근접성을 이용한 효율적인 버퍼 관리 기법)

  • Min, Jun-Ki
    • The KIPS Transactions:PartD
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    • v.16D no.2
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    • pp.153-160
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    • 2009
  • Efficient buffer management is closely related to system performance. Thus, much research has been performed on various buffer management techniques. However, many of the proposed techniques utilize the temporal locality of access patterns. In spatial database environments, there exists not only the temporal locality but also spatial locality, where the objects in the recently accessed regions will be accessed again in the near future. Thus, in this paper, we present a buffer management technique, called BEAT, which utilizes both the temporal locality and spatial locality in spatial database environments. The experimental results with real-life and synthetic data demonstrate the efficiency of BEAT.

Dual Cache Architecture for Low Cost and High Performance

  • Lee, Jung-Hoon;Park, Gi-Ho;Kim, Shin-Dug
    • ETRI Journal
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    • v.25 no.5
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    • pp.275-287
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    • 2003
  • We present a high performance cache structure with a hardware prefetching mechanism that enhances exploitation of spatial and temporal locality. Temporal locality is exploited by selectively moving small blocks into the direct-mapped cache after monitoring their activity in the spatial buffer. Spatial locality is enhanced by intelligently prefetching a neighboring block when a spatial buffer hit occurs. We show that the prefetch operation is highly accurate: over 90% of all prefetches generated are for blocks that are subsequently accessed. Our results show that the system enables the cache size to be reduced by a factor of four to eight relative to a conventional direct-mapped cache while maintaining similar performance.

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Multiscale Spatial Position Coding under Locality Constraint for Action Recognition

  • Yang, Jiang-feng;Ma, Zheng;Xie, Mei
    • Journal of Electrical Engineering and Technology
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    • v.10 no.4
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    • pp.1851-1863
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    • 2015
  • – In the paper, to handle the problem of traditional bag-of-features model ignoring the spatial relationship of local features in human action recognition, we proposed a Multiscale Spatial Position Coding under Locality Constraint method. Specifically, to describe this spatial relationship, we proposed a mixed feature combining motion feature and multi-spatial-scale configuration. To utilize temporal information between features, sub spatial-temporal-volumes are built. Next, the pooled features of sub-STVs are obtained via max-pooling method. In classification stage, the Locality-Constrained Group Sparse Representation is adopted to utilize the intrinsic group information of the sub-STV features. The experimental results on the KTH, Weizmann, and UCF sports datasets show that our action recognition system outperforms the classical local ST feature-based recognition systems published recently.

Reversible data hiding algorithm using spatial locality and the surface characteristics of image

  • Jung, Soo-Mok;On, Byung-Won
    • Journal of the Korea Society of Computer and Information
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    • v.21 no.8
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    • pp.1-12
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    • 2016
  • In this paper, we propose a very efficient reversible data hiding algorithm using spatial locality and the surface characteristics of image. Spacial locality and a variety of surface characteristics are present in natural images. So, it is possible to precisely predict the pixel value using the locality and surface characteristics of image. Therefore, the frequency is increased significantly at the peak point of the difference histogram using the precisely predicted pixel values. Thus, it is possible to increase the amount of data to be embedded in image using the spatial locality and surface characteristics of image. By using the proposed reversible data hiding algorithm, visually high quality stego-image can be generated, the embedded data and the original cover image can be extracted without distortion from the stego-image, and the embedding data are much greater than that of the previous algorithm. The experimental results show the superiority of the proposed algorithm.

High Performance Data Cache Memory Architecture (고성능 데이터 캐시 메모리 구조)

  • Kim, Hong-Sik;Kim, Cheong-Ghil
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.9 no.4
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    • pp.945-951
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    • 2008
  • In this paper, a new high performance data cache scheme that improves exploitation of both the spatial and temporal locality is proposed. The proposed data cache consists of a hardware prefetch unit and two sub-caches such as a direct-mapped (DM) cache with a large block size and a fully associative buffer with a small block size. Spatial locality is exploited by fetching and storing large blocks into a direct mapped cache, and is enhanced by prefetching a neighboring block when a DM cache hit occurs. Temporal locality is exploited by storing small blocks from the DM cache in the fully associative buffer according to their activity in the DM cache when they are replaced. Experimental results on Spec2000 programs show that the proposed scheme can reduce the average miss ratio by $12.53%\sim23.62%$ and the AMAT by $14.67%\sim18.60%$ compared to the previous schemes such as direct mapped cache, 4-way set associative cache and SMI(selective mode intelligent) cache[8].

A Clustering Method for Optimizing Spatial Locality (공간국부성을 최적화하는 클러스터링 방법)

  • 김홍기
    • Journal of KIISE:Databases
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    • v.31 no.2
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    • pp.83-90
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    • 2004
  • In this paper, we study the CCD(Clustering with Circular Distance) and the COD(Clustering with Obstructed Distance) problems to be considered when objects are being clustered in a circularly search space and a search space with the presence of obstacles. We also propose a now clustering algorithm for clustering efficiently objects that the insertion or the deletion is occurring frequently in multi-dimensional search space. The distance function for solving the CCD and COD Problems is defined in the Proposed clustering algorithm. This algorithm is included a clustering method to create clusters that have a high spatial locality by minimum computation time.

A Study of Efficient Access Method based upon the Spatial Locality of Multi-Dimensional Data

  • Yoon, Seong-young;Joo, In-hak;Choy, Yoon-chul
    • Proceedings of the Korea Database Society Conference
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    • 1997.10a
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    • pp.472-482
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    • 1997
  • Multi-dimensional data play a crucial role in various fields, as like computer graphics, geographical information system, and multimedia applications. Indexing method fur multi-dimensional data Is a very Important factor in overall system performance. What is proposed in this paper is a new dynamic access method for spatial objects called HL-CIF(Hierarchically Layered Caltech Intermediate Form) tree which requires small amount of storage space and facilitates efficient query processing. HL-CIF tree is a combination of hierarchical management of spatial objects and CIF tree in which spatial objects and sub-regions are associated with representative points. HL-CIF tree adopts "centroid" of spatial objects as the representative point. By reflecting objects′sizes and positions in its structure, HL-CIF tree guarantees the high spatial locality of objects grouped in a sub-region rendering query processing more efficient.

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Spatial Locality Preservation Metric for Constructing Histogram Sequences (히스토그램 시퀀스 구성을 위한 공간 지역성 보존 척도)

  • Lee, Jeonggon;Kim, Bum-Soo;Moon, Yang-Sae;Choi, Mi-Jung
    • Journal of Information Technology and Architecture
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    • v.10 no.1
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    • pp.79-91
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    • 2013
  • This paper proposes a systematic methodology that could be used to decide which one shows the best performance among space filling curves (SFCs) in applying lower-dimensional transformations to histogram sequences. A histogram sequence represents a time-series converted from an image by the given SFC. Due to the high-dimensionality nature, histogram sequences are very difficult to be stored and searched in their original form. To solve this problem, we generally use lower-dimensional transformations, which produce lower bounds among high dimensional sequences, but the tightness of those lower-bounds is highly affected by the types of SFC. In this paper, we attack a challenging problem of evaluating which SFC shows the better performance when we apply the lower-dimensional transformation to histogram sequences. For this, we first present a concept of spatial locality, which comes from an intuition of "if the entries are adjacent in a histogram sequence, their corresponding cells should also be adjacent in its original image." We also propose spatial locality preservation metric (slpm in short) that quantitatively evaluates spatial locality and present its formal computation method. We then evaluate five SFCs from the perspective of slpm and verify that this evaluation result concurs with the performance evaluation of lower-dimensional transformations in real image matching. Finally, we perform k-NN (k-nearest neighbors) search based on lower-dimensional transformations and validate accuracy of the proposed slpm by providing that the Hilbert-order with the highest slpm also shows the best performance in k-NN search.

A Location Tracking Strategy with Spatial Locality in Personal Communication Networks (개인휴대 통신망에서 공간적 국부성을 이용한 위치추적 방법)

  • Lee, Jong-Min;Kwon, Bo-Seob;Maeng, Seung-Ryoul
    • The KIPS Transactions:PartC
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    • v.10C no.2
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    • pp.191-198
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    • 2003
  • Location tracking is used to keep track of the location information of a mobile terminal in an idle state for a call setup between mobile terminals. In this paper, we introduce a new location tracking strategy that utilizes spatial locality to have better performance than a movement based location tracking strategy. We reduce a lot of unnecessary location updates by updating the location information of a mobile terminal using the virtual movement path, which is generated after removing spatial localities in the actual movement path. Simulation results show that the proposed strategy greatly reduces the overall location tracking cost.