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A well-known fact in the field of lossless text compression is that high-order entropy is a weak model when the input contains long repetitions. Motivated by this, decades of research have generated myriads of so-called dictionary…

Data Structures and Algorithms · Computer Science 2020-12-17 Dominik Kempa , Nicola Prezza

Wu and Verd\'u developed a theory of almost lossless analog compression, where one imposes various regularity conditions on the compressor and the decompressor with the input signal being modelled by a (typically infinite-entropy)…

Dynamical Systems · Mathematics 2022-12-29 Yonatan Gutman , Adam Śpiewak

We explore an extension to straight-line programs (SLPs) that outperforms, for some text families, the measure $\delta$ based on substring complexity, a lower bound for most measures and compressors exploiting repetitiveness (which are…

Data Structures and Algorithms · Computer Science 2024-02-16 Gonzalo Navarro , Cristian Urbina

In this paper we investigate the problem of building a static data structure that represents a string s using space close to its compressed size, and allows fast access to individual characters of s. This type of structures was investigated…

Computational Complexity · Computer Science 2012-05-04 Shiteng Chen , Elad Verbin , Wei Yu

The notion of string attractor has been introduced in [Kempa and Prezza, 2018] in the context of Data Compression and it represents a set of positions of a finite word in which all of its factors can be "attracted". The smallest size…

Formal Languages and Automata Theory · Computer Science 2022-06-02 Antonio Restivo , Giuseppe Romana , Marinella Sciortino

Motivated by the observation that a given signal $\boldsymbol{x}$ admits sparse representations in multiple dictionaries $\boldsymbol{\Psi}_d$ but with varying levels of sparsity across dictionaries, we propose two new algorithms for the…

Information Theory · Computer Science 2015-09-29 Rizwan Ahmad , Philip Schniter

In 2009, a lossless compression algorithm based on 1D chaotic maps known as Generalized Lur\"{o}th Series (or GLS) has been proposed. This algorithm (GLS-coding) encodes the input message as a symbolic sequence on an appropriate 1D chaotic…

Information Theory · Computer Science 2013-08-13 Nithin Nagaraj

Lindenmayer systems (L-systems) are a grammar system that consist of string rewriting rules. The rules replace every symbol in a string in parallel with a successor to produce the next string, and this procedure iterates. In a stochastic…

Artificial Intelligence · Computer Science 2020-01-30 Jason Bernard , Ian McQuillan

The unrestricted LZ78 universal data-compression algorithm (as well as the LZ77 and LZW versions) achieves asymptotically, as the block-length tends to infinity, the FS compressibility, namely the best compression-ratio that may be achieved…

Information Theory · Computer Science 2015-03-16 Jacob Ziv

The goal of compressed sensing is to estimate a vector from an underdetermined system of noisy linear measurements, by making use of prior knowledge on the structure of vectors in the relevant domain. For almost all results in this…

Machine Learning · Statistics 2017-03-10 Ashish Bora , Ajil Jalal , Eric Price , Alexandros G. Dimakis

We consider an important problem in signal processing, which consists in finding the sparsest solution of a linear system $\Phi x=b$. This problem has applications in several areas, but is NP-hard in general. Usually an alternative convex…

Optimization and Control · Mathematics 2019-06-25 Matías Valdés , Marcelo Fiori

Universal compression of patterns of sequences generated by independently identically distributed (i.i.d.) sources with unknown, possibly large, alphabets is investigated. A pattern is a sequence of indices that contains all consecutive…

Information Theory · Computer Science 2016-11-17 Gil I. Shamir

Let $S_{T}(k)$ denote the set of distinct substrings of length $k$ in a string $T$, then the $k$-th substring complexity is defined by its cardinality $|S_{T}(k)|$. Recently, $\delta = \max \{ |S_{T}(k)| / k : k \ge 1 \}$ is shown to be a…

Data Structures and Algorithms · Computer Science 2022-05-26 Akiyoshi Kawamoto , Tomohiro I

We consider the problem of finding an approximate solution to $\ell_1$ regression while only observing a small number of labels. Given an $n \times d$ unlabeled data matrix $X$, we must choose a small set of $m \ll n$ rows to observe the…

Machine Learning · Computer Science 2021-05-21 Aditya Parulekar , Advait Parulekar , Eric Price

We study how much a linear program (LP) can be compressed when solved repeatedly, given prior knowledge about its objective function. Existing data-driven projection methods learn low-dimensional surrogate LPs with approximate…

Optimization and Control · Mathematics 2026-05-26 Yuhan Ye , Omar Bennouna

Two important similarity measures between sequences are the longest common subsequence (LCS) and the dynamic time warping distance (DTWD). The computations of these measures for two given sequences are central tasks in a variety of…

Computational Complexity · Computer Science 2015-02-02 Amir Abboud , Arturs Backurs , Virginia Vassilevska Williams

A quasi-Gray code of dimension $n$ and length $\ell$ over an alphabet $\Sigma$ is a sequence of distinct words $w_1,w_2,\dots,w_\ell$ from $\Sigma^n$ such that any two consecutive words differ in at most $c$ coordinates, for some fixed…

Information Theory · Computer Science 2018-07-18 Diptarka Chakraborty , Debarati Das , Michal Koucký , Nitin Saurabh

Let $W^{(n)}$ be the $n$-letter word obtained by repeating a fixed word $W$, and let $R_n$ be a random $n$-letter word over the same alphabet. We show several results about the length of the longest common subsequence (LCS) between…

Probability · Mathematics 2021-06-07 Boris Bukh , Christopher Cox

In-context learning has established itself as an important learning paradigm for Large Language Models (LLMs). In this paper, we demonstrate that LLMs can learn encoding keys in-context and perform analysis directly on encoded…

Computation and Language · Computer Science 2026-04-16 Andresa Rodrigues de Campos , David Lee , Imry Kissos , Piyush Paritosh

Data compression algorithms are generally perceived as being of interest for data communication and storage purposes only. However, their use in the field of data classification and analysis is also of equal importance. Automatic data…