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A Space Efficient Direct Access Data Structure

Gilad Baruch, Shmuel T. Klein, Dana Shapira
2016 2016 Data Compression Conference (DCC)  
Given a file T , we suggest a data structure based on pruning a Huffman shaped Wavelet tree (WT) according to the underlying skeleton Huffman tree that enables direct access to the i-th element of T .  ...  We give empirical evidence that when memory storage is of main concern, our suggested data structure outperforms other direct access techniques such as those due to Külekci, dacs and sampling, with a slowdown  ...  [13] , is a data structure which reorders the bits of the compressed file into an alternative form, thereby enabling direct access, as well as other efficient operations.  ... 
doi:10.1109/dcc.2016.61 dblp:conf/dcc/BaruchKS16 fatcat:37u65toapjbqnnj6iu3253xs6e

Indexing Temporal Data with Virtual Structure [chapter]

Bela Stantic, Justin Terry, Rodney Topor, Abdul Sattar
2010 Lecture Notes in Computer Science  
In this paper, we investigate and present a new concept based on virtual index structure, which can efficiently query such data.  ...  Concept is based on spatial representation of interval data and a recursive triangular decomposition of that space.  ...  It is our intention to propose an efficient access method for temporal data with logarithmic access time and guaranteed minimum space complexity that can answer a wide range of query types with the same  ... 
doi:10.1007/978-3-642-15576-5_53 fatcat:vijbk2b3frgmfml2v5ybdr77mq

AN INDOOR SPACE PARTITION METHOD AND ITS FINGERPRINT POSITIONING OPTIMIZATION CONSIDERING PEDESTRIAN ACCESSIBILITY

Yue Xu, Yong Shi, Xingyu Zheng, Yi Long
2016 The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences  
A across linker structure was used for fingerprint point index and matching.  ...  This paper studied these two issues, proposed a new indoor space partition method considering pedestrian accessibility, which can increase the accuracy of pedestrian position, and decrease the volume of  ...  With this structure we furtherly define data structure of indoor space, Every element in the across linker has a precursor and a subsequence in both vertical and horizontal axis.  ... 
doi:10.5194/isprs-archives-xli-b4-347-2016 fatcat:lxuy3yaeyndjpaggyuo5kawnv4

AN INDOOR SPACE PARTITION METHOD AND ITS FINGERPRINT POSITIONING OPTIMIZATION CONSIDERING PEDESTRIAN ACCESSIBILITY

Yue Xu, Yong Shi, Xingyu Zheng, Yi Long
2016 The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences  
A across linker structure was used for fingerprint point index and matching.  ...  This paper studied these two issues, proposed a new indoor space partition method considering pedestrian accessibility, which can increase the accuracy of pedestrian position, and decrease the volume of  ...  With this structure we furtherly define data structure of indoor space, Every element in the across linker has a precursor and a subsequence in both vertical and horizontal axis.  ... 
doi:10.5194/isprsarchives-xli-b4-347-2016 fatcat:immuf7fvjzfmta7fohqasjui3i

Dymaxion++: A Directive-Based API to Optimize Data Layout and Memory Mapping for Heterogeneous Systems

Shuai Che, Jiayuan Meng, Kevin Skadron
2014 2014 IEEE International Parallel & Distributed Processing Symposium Workshops  
Dymaxion++ also provides additional programming features to map data structures to GPU's hybrid memory spaces (e.g. texture and constant memory) for different uses.  ...  This paper proposes a directive-based API, Dymaxion++, which enables programmers to optimize memory access patterns across devices with a simple interface.  ...  The data structure is reorganized into a different shape in memory that is ideal for memory accesses. • The memory-space mapping (place) model allows programmers to map data structures to different memory  ... 
doi:10.1109/ipdpsw.2014.104 dblp:conf/ipps/CheMS14 fatcat:ziimpugoenczza3pazofvpvnx4

An empirical assessment of approaches to distributed enforcement in role-based access control (RBAC)

Marko Komlenovic, Mahesh Tripunitara, Toufik Zitouni
2011 Proceedings of the first ACM conference on Data and application security and privacy - CODASPY '11  
We present our results from an empirical assessment of time, space and administrative efficiency based on the benchmark.  ...  The approaches are: directed graph, access matrix, authorization recycling, CPOL, Bloom filter and cascade Bloom filter.  ...  Time efficiency -our primary goal is to make the SDP time efficient. An access check should be fast. Space efficiency -we consider also the space that a particular data structure may take at the SDP.  ... 
doi:10.1145/1943513.1943530 dblp:conf/codaspy/KomlenovicTZ11 fatcat:ddixh4rygfh3djqo3hsh4ftmge

A Tale of Two Abstractions: The Case for Object Space

Daniel Bittman, Peter Alvaro, Darrell D. E. Long, Ethan L. Miller
2019 USENIX Workshop on Hot Topics in Storage and File Systems  
We propose to abstract physical memory into an object space, which maps objects to physical memory, while providing applications with a way to refer to data that may have a lifetime longer than the processes  ...  Both abstractions must be implemented in a way that is efficient using existing hardware.  ...  The direct access nature of BNVM enables low-latency, memory-style access to persistent data, in which memorystyle data structures may have indefinitely long lifetimes.  ... 
dblp:conf/hotstorage/BittmanALM19 fatcat:ajqn6a2yn5b7bfzwpry6tbj7jy

Advanced indexing technique for temporal data

Bela Stantic, Rodney Topor, Justin Terry, Abdul Sattar
2010 Computer Science and Information Systems  
The need for efficient access and management of time dependent data in modern database applications is well recognised and researched.  ...  The underlying idea for the TD-Tree is to manage temporal intervals by virtual index structures relying on geometric interpretations of intervals, and a space partition method that results in an unbalanced  ...  It is our intention to propose an efficient access method for temporal data with logarithmic access time and guaranteed minimum space complexity that can answer a wide range of query types with the same  ... 
doi:10.2298/csis101020035s fatcat:5b4nkuw7xjg57of2drc42l3qfy

A model for the prediction of R-tree performance

Yannis Theodoridis, Timos Sellis
1996 Proceedings of the fifteenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems - PODS '96  
., the proposed formula that estimates the number of disk accesses is a function of data properties, namely, the amount of data and their density in the work space.  ...  We believe that this error is involved with the gap between efficient R-tree variants, like the R*-tree, and an optimum, not implemented yet, method.  ...  axis disk accesses query size in % of work space per axis disk accesses query size in % of work space per axis disk accesses (a) Random data: D = 0.1, N = 40K (lower pair) and 80K (upper pair) (b) Skewed  ... 
doi:10.1145/237661.237705 dblp:conf/pods/TheodoridisS96 fatcat:w4erao4tzrehtmy2xbhil634ym

A Spatio-Temporal Local Association Query Algorithm for Multi-Source Remote Sensing Big Data

Lilu Zhu, Xiaolu Su, Yanfeng Hu, Xianqing Tai, Kun Fu
2021 Remote Sensing  
It is extremely important to extract valuable information and achieve efficient integration of remote sensing data.  ...  Firstly, we design a spatio-temporal data model and a bottom-up spatio-temporal correlation network.  ...  We use Apache JMeter as the performance testing tool to continuously access the data query interface, to test the retrieval efficiency of three different index structures.  ... 
doi:10.3390/rs13122333 fatcat:6rnv3auwhbh2hbet6myxjawfaq

The Grid File: An Adaptable, Symmetric Multikey File Structure

J. Nievergelt, Hans Hinterberger, Kenneth C. Sevcik
1984 ACM Transactions on Database Systems  
This leads to the notions of a grid partition of the search space and of a grid directory, which are the keys to a dynamic file structure called the grid file.  ...  We start from a bitmap approach and treat the problem of file design as one of data compression of a large sparse matrix.  ...  In summary: -range queries demand grid partitions of the search space, -efficient update after modification of a grid partition demands conuex assignments of grid blocks to data buchets, -the two-disk-access  ... 
doi:10.1145/348.318586 fatcat:hzlg2b7ebjavjbyk2cxugnzdxi

The grid file: An adaptable, symmetric multi-key file structure [chapter]

J. Nievergelt, H. Hinterberger, K. C. Sevcik
1981 Lecture Notes in Computer Science  
This leads to the notions of a grid partition of the search space and of a grid directory, which are the keys to a dynamic file structure called the grid file.  ...  We start from a bitmap approach and treat the problem of file design as one of data compression of a large sparse matrix.  ...  In summary: -range queries demand grid partitions of the search space, -efficient update after modification of a grid partition demands conuex assignments of grid blocks to data buchets, -the two-disk-access  ... 
doi:10.1007/3-540-10885-8_45 fatcat:kj4n3qk6ofegheoaakiyto54bu

Speed up linear scan in high-dimensions by sorting one-dimensional projections

Jiangtao Cui, Bin Xiao, Gengdai Liu, Lian Jiang
2011 International Journal of Intelligent Systems and Applications  
In the new search algorithm, only a small portion of data points need to be linearly accessed by computing the bounded distance on the one-dimensional line, which can reduce the I/O and processor time  ...  In this paper, we propose a new access idea implemented on linear scan based methods to speed up the nearest-neighbor queries.  ...  In this paper, we proposed a simple and efficient index structure based on extended B + -tree, which can facilitate efficient k-NN searches in high-dimensional space.  ... 
doi:10.5815/ijisa.2011.04.06 fatcat:zua6gyeqkjag3ev3v66276sfnm

DACs: Bringing direct access to variable-length codes

Nieves R. Brisaboa, Susana Ladra, Gonzalo Navarro
2013 Information Processing & Management  
Our proposal is a kind of implicit data structure that introduces synchronism in the encoded sequence without using asymptotically any extra space.  ...  We present a new variable-length encoding scheme for sequences of integers, Directly Addressable Codes (DACs), which enables direct access to any element of the encoded sequence without the need of any  ...  extra space for rank structures), that enables direct access to it.  ... 
doi:10.1016/j.ipm.2012.08.003 fatcat:nshc4t7qsvf7laqyihd4y5qgia

On the Flexible 5G Dense Deployment Air Interface for Mobile Broadband

Eeva Lähetkangas, Kari Pajukoski, Jaakko Vihriälä, Esa Tiirola
2014 Proceedings of the 1st International Conference on 5G for Ubiquitous Connectivity  
The subframe structure consists of time separated control and data, enabling low latency, flexible UL/DL ratio switching and high spectral efficiency with low cost transceiver.  ...  Index Terms-3GPP, 5G, energy consumption, frame structure, harmonized OFDM, latency, local area, LTE, RAT, subcarrier spacing, TDD, TTI. I.  ...  Fig. 2 . 2 Spectral efficiency as a function of CP length for InH. Fig. 3 . 3 Spectral efficiency as a function of CP length for UMa. Fig. 4 . 4 Optimal CP length and subcarrier spacing.  ... 
doi:10.4108/icst.5gu.2014.258101 dblp:conf/5gu/LahetkangasPVT14 fatcat:aszuydvmknhzpicam52ddt6ove
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