English
Related papers

Related papers: Hybrid Indexes for Repetitive Datasets

200 papers

This article introduces a new DNA sequence compression algorithm which is based on LUT and LZ77 algorithm. Combined a LUT-based pre-coding routine and LZ77 compression routine,this algorithm can approach a compression ratio of 1.9bits…

Information Theory · Computer Science 2007-07-16 Sheng Bao , Shi Chen , Zhiqiang Jing , Ran Ren

We introduce a new approach to LZ77 factorization that uses O(n/d) words of working space and O(dn) time for any d >= 1 (for polylogarithmic alphabet sizes). We also describe carefully engineered implementations of alternative approaches to…

Data Structures and Algorithms · Computer Science 2020-12-11 Juha Kärkkäinen , Dominik Kempa , Simon J. Puglisi

Lempel-Ziv (LZ77 or, briefly, LZ) is one of the most effective and widely-used compressors for repetitive texts. However, the existing efficient methods computing the exact LZ parsing have to use linear or close to linear space to index the…

Data Structures and Algorithms · Computer Science 2020-05-12 Dmitry Kosolobov , Daniel Valenzuela , Gonzalo Navarro , Simon J. Puglisi

In this work, we propose an approach to index Deep Convolutional Neural Network Features to support efficient content-based retrieval on large image databases. To this aim, we have converted the these features into a textual form, to index…

Computer Vision and Pattern Recognition · Computer Science 2016-07-21 Claudio Gennaro

Motivation The Burrows-Wheeler transform (BWT) is the foundation of many algorithms for compression and indexing of text data, but the cost of computing the BWT of very large string collections has prevented these techniques from being…

Data Structures and Algorithms · Computer Science 2015-03-20 Anthony J. Cox , Markus J. Bauer , Tobias Jakobi , Giovanna Rosone

In this paper we describe a data structure that supports pattern matching queries on a dynamically arriving text over an alphabet ofconstant size. Each new symbol can be prepended to $T$ in O(1) worst-case time. At any moment, we can report…

Data Structures and Algorithms · Computer Science 2013-07-09 Gregory Kucherov , Yakov Nekrich

In recent years the importance of finding a meaningful pattern from huge datasets has become more challenging. Data miners try to adopt innovative methods to face this problem by applying feature selection methods. In this paper we propose…

Machine Learning · Computer Science 2014-03-11 Mehdi Naseriparsa , Amir-masoud Bidgoli , Touraj Varaee

Data compression is a powerful tool for managing massive but repetitive datasets, especially schemes such as grammar-based compression that support computation over the data without decompressing it. In the best case such a scheme takes a…

Data Structures and Algorithms · Computer Science 2019-06-04 Travis Gagie , Tomohiro I , Giovanni Manzini , Gonzalo Navarro , Hiroshi Sakamoto , Yoshimasa Takabatake

The problem of Text Indexing is a fundamental algorithmic problem in which one wishes to preprocess a text in order to quickly locate pattern queries within the text. In the ever evolving world of dynamic and on-line data, there is also a…

Data Structures and Algorithms · Computer Science 2012-08-21 Tsvi Kopelowitz

Inverted indexes allow to query large databases without needing to search in the database at each query. An important line of research is to construct the most efficient inverted indexes, both in terms of compression ratio and time…

Databases · Computer Science 2025-05-06 Yann Barsamian , André Chailloux

Grammar-based compression is a popular and powerful approach to compressing repetitive texts but until recently its relatively poor time-space trade-offs during real-life construction made it impractical for truly massive datasets such as…

Data Structures and Algorithms · Computer Science 2020-07-21 Travis Gagie , Tomohiro I , Giovanni Manzini , Gonzalo Navarro , Hiroshi Sakamoto , Louisa Seelbach Benkner , Yoshimasa Takabatake

In highly repetitive strings, like collections of genomes from the same species, distinct measures of repetition all grow sublinearly in the length of the text, and indexes targeted to such strings typically depend only on one of these…

Data Structures and Algorithms · Computer Science 2015-02-24 Djamal Belazzougui , Fabio Cunial , Travis Gagie , Nicola Prezza , Mathieu Raffinot

The main contribution of this paper is to design an Information Retrieval (IR) technique based on Algorithmic Information Theory (using the Normalized Compression Distance- NCD), statistical techniques (outliers), and novel organization of…

Information Retrieval · Computer Science 2016-11-17 Rafael Martinez , Manuel Cebrian , Francisco de Borja Rodriguez , David Camacho

We consider document listing on string collections, that is, finding in which strings a given pattern appears. In particular, we focus on repetitive collections: a collection of size $N$ over alphabet $[1,\sigma]$ is composed of $D$ copies…

Data Structures and Algorithms · Computer Science 2018-11-15 Gonzalo Navarro

Efficient text indexing data structures have enabled large-scale genomic sequence analysis and are used to help solve problems ranging from assembly to read mapping. However, these data structures typically assume that the underlying…

Genomics · Quantitative Biology 2016-04-13 Nitish Gupta , Komal Sanjeev , Tim Wall , Carl Kingsford , Rob Patro

Relative Lempel-Ziv (RLZ) is a popular algorithm for compressing databases of genomes from individuals of the same species when fast random access is desired. With Kuruppu et al.'s (SPIRE 2010) original implementation, a reference genome is…

Data Structures and Algorithms · Computer Science 2016-05-17 Anthony J. Cox , Andrea Farruggia , Travis Gagie , Simon J. Puglisi , Jouni Sirén

Many services today massively and continuously produce log files of different and varying formats. These logs are important since they contain information about the application activities, which is necessary for improvements by analyzing…

Information Retrieval · Computer Science 2023-04-11 Igor Cherepanov , Jonathan Geraldi Joewono , Arjan Kuijper , Jörn Kohlhammer

Next Generation Sequencing (NGS) platforms and, more generally, high-throughput technologies are giving rise to an exponential growth in the size of nucleotide sequence databases. Moreover, many emerging applications of nucleotide datasets…

Databases · Computer Science 2019-10-11 Ferdinando Montecuollo , Giovannni Schmid , Roberto Tagliaferri

Computing the LZ factorization (or LZ77 parsing) of a string is a computational bottleneck in many diverse applications, including data compression, text indexing, and pattern discovery. We describe new linear time LZ factorization…

Data Structures and Algorithms · Computer Science 2020-12-11 Juha Kärkkäinen , Dominik Kempa , Simon J. Puglisi

Motivated by the imminent growth of massive, highly redundant genomic databases, we study the problem of compressing a string database while simultaneously supporting fast random access, substring extraction and pattern matching to the…

Data Structures and Algorithms · Computer Science 2012-11-01 Travis Gagie , Paweł Gawrychowski , Christopher Hoobin , Simon J. Puglisi