Search results for "Theoretical Computer Science"

On parsing optimality for dictionary-based text compression—the Zip case

2013

Dictionary-based compression schemes are the most commonly used data compression schemes since they appeared in the foundational paper of Ziv and Lempel in 1977, and generally referred to as LZ77. Their work is the base of Zip, gZip, 7-Zip and many other compression software utilities. Some of these compression schemes use variants of the greedy approach to parse the text into dictionary phrases; others have left the greedy approach to improve the compression ratio. Recently, two bit-optimal parsing algorithms have been presented filling the gap between theory and best practice. We present a survey on the parsing problem for dictionary-based text compression, identifying noticeable results …

Probabilistic versus deterministic memory limited learning

1995

On implicit data structures for priority queues

1985

Comparaison avec une structure liee simple et implementation de certaines structures de donnees implicites pour les files d'attente de priorite. Le minutage des experiences montre que les structures implicites sont plutot lentes

Universal multipartite d-level entanglement witnesses for realistic measurement settings

2019

Entanglement is an essential resource in quantum information science [1] and its presence in any quantum system can be experimentally detected through entanglement witness operators [2]. In particular, measuring a negative expectation value of a witness with high statistical confidence provides a necessary and sufficient condition to confirm the generation of a genuine multipartite [3] and/or d-level entangled state [4]. In recent years, the experimental generation of complex quantum states has intensified the need for witnesses that are capable of detecting such systems and are experimentally optimal at the same time. This means that the witness should require the least measurement effort …

Supporting mathematical modelling by upscaling real context in a sequence of tasks

2021

AbstractCreating and developing mathematical models to solve real-world problems is a complex task and students often have difficulties in tackling it successfully. The design and implementation of sequences that help students autonomously develop their ability to solve modelling tasks could be a useful scaffolding tool to foster modelling learning. In this paper we present a sequence of estimation tasks in a real context based on what we have called the upscaling technique, which consists of scaling the accessibility and knowledge of the context used. A study with two samples of grade 10 students, experimental and control, has allowed us to find out whether this sequence promotes success i…

A model of adaptive decision-making from representation of information environment by quantum fields

2017

We present the mathematical model of decision making (DM) of agents acting in a complex and uncertain environment (combining huge variety of economical, financial, behavioral, and geo-political factors). To describe interaction of agents with it, we apply the formalism of quantum field theory (QTF). Quantum fields are of the purely informational nature. The QFT-model can be treated as a far relative of the expected utility theory, where the role of utility is played by adaptivity to an environment (bath). However, this sort of utility-adaptivity cannot be represented simply as a numerical function. The operator representation in Hilbert space is used and adaptivity is described as in quantu…

On the role of non-effective code in linear genetic programming

2019

In linear variants of Genetic Programming (GP) like linear genetic programming (LGP), structural introns can emerge, which are nodes that are not connected to the final output and do not contribute to the output of a program. There are claims that such non-effective code is beneficial for search, as it can store relevant and important evolved information that can be reactivated in later search phases. Furthermore, introns can increase diversity, which leads to higher GP performance. This paper studies the role of non-effective code by comparing the performance of LGP variants that deal differently with non-effective code for standard symbolic regression problems. As we find no decrease in p…

Efficient evaluation for a subset of recursive queries

1991

Abstract We consider the efficient evaluation of recursive queries in logic databases where the queries are expressed using a Datalog program (function-free Horn-clause program) that contains only regularly or linearly recursive predicates. Using well-known results on graph traversal, we develop an efficient algorithm for evaluating relations defined by a binary-chain program. We also present a transformation by which the evaluation of a subset of queries involving nonbinary relations can be reduced to the evaluation of binary-chain queries. This transformation is guided by the choice of bound arguments in the query, and the bindings are propagated through the program so that in the evaluat…

An inductive inference approach to classification

1992

In this paper, we introduce a formal framework for investigating the relationship of inductive inference and the task of classification. We give the first results on the relationship between functions that can be identified in the limit and functions that can be acquired from unclassified objects only. Moreover, we present results on the complexity of classification functions and the preconditions necessary in order to allow the computation of such functions.

Abstraction in Motion

2015

Folding Pattern is an art project developed by the team of artists, Cristina Ghetti and Emanuele Mazza. The work starts from the idea of proposing a revision of the foundations of perceptual abstraction, that had in it's derivations, one of the art movements more connected with the use of new technologies and one of the art tendencies with more powerful and interesting arguments. We are interested in exploring the developments of abstraction in the digital era, incorporating new media tools, and analyzing how contemporary art is developing the ideas of modernist abstraction introducing the utilization of new technologies, in a context where the influence of science, and of new ways of produ…