Search results for " Complexity"
showing 10 items of 623 documents
The average state complexity of rational operations on finite languages is linear
2010
Considering the uniform distribution on sets of m non-empty words whose sum of lengths is n, we establish that the average state complexities of the rational operations are asymptotically linear.
Varieties Generated by Certain Models of Reversible Finite Automata
2006
Reversible finite automata with halting states (RFA) were first considered by Ambainis and Freivalds to facilitate the research of Kondacs-Watrous quantum finite automata. In this paper we consider some of the algebraic properties of RFA, namely the varieties these automata generate. Consequently, we obtain a characterization of the boolean closure of the classes of languages recognized by these models.
Adding Transitivity and Counting to the Fluted Fragment
2023
We study the impact of adding both counting quantifiers and a single transitive relation to the fluted fragment - a fragment of first-order logic originating in the work of W.V.O. Quine. The resulting formalism can be viewed as a multi-variable, non-guarded extension of certain systems of description logic featuring number restrictions and transitive roles, but lacking role-inverses. We establish the finite model property for our logic, and show that the satisfiability problem for its k-variable sub-fragment is in (k+1)-NExpTime. We also derive ExpSpace-hardness of the satisfiability problem for the two-variable, fluted fragment with one transitive relation (but without counting quantifiers…
REMOTELY PILOTED AIRCRAFT SYSTEMS (RPAS) APPLICATION FOR STRUCTURE DESCRIPTION OF MEDITERRANEAN VERMETID REEFS
2016
Vermetid gastropods are coastal habitat engineers which build biogenic platforms typical of intertidal rocky shores of central and south -east of the Mediterranean. These bioconstructions create a secondary habitat which increases resource availability and space for organisms, locally transforming the environment and modifying coastal geomorphology. Biological characteristics and physical structure of these bioconstructions are commonly studied by field-based sampling. Nevertheless, a lot of time is required to collect data over large areas of reef, field conditions can impair data collection and direct reef image interpretation may be a challenge due to their intertidal position. In this s…
La complejidad del conocimiento: retos para su eficaz creación y transferencia en la organización innovadora
2012
Una eficaz creación y transferencia de conocimiento es esencial para promover el aprendizaje organizativo y la innovación. Con este postulado como idea principal, este artículo explora sendos casos de proyectos de gestión del conocimiento en dos empresas españolas, profundizando en tres características problemáticas del conocimiento: dispersión, ambigüedad y perturbación. Los resultados recomiendan diseñar cuidadosamente el proyecto de gestión de conocimiento teniendo en cuenta: (i) el propósito de la estrategia de gestión de conocimiento, (ii) el equipo coordinador del proyecto y la distribución de responsabilidades, y (iii) los requerimientos y restricciones organizativos, incluyendo proc…
Earnings Premiums in Academia: Evidence from Personnel Data
2013
This study examines the existence of a gender earnings gap in the academic labour market with well-defined pay scales with panel data from the personnel records of a large university. We find that women earn approximately 10% less than men but that adjusting for different background characteristics and research performance decreases the gap to 2%. Our results suggest that the level of gender pay inequality is greater among older employees and lower for more productive employees. The results also imply that the gender gap is more pronounced in female-led departments than in male-led departments. peerReviewed
A New Feature Selection Methodology for K-mers Representation of DNA Sequences
2015
DNA sequence decomposition into k-mers and their frequency counting, defines a mapping of a sequence into a numerical space by a numerical feature vector of fixed length. This simple process allows to compare sequences in an alignment free way, using common similarities and distance functions on the numerical codomain of the mapping. The most common used decomposition uses all the substrings of a fixed length k making the codomain of exponential dimension. This obviously can affect the time complexity of the similarity computation, and in general of the machine learning algorithm used for the purpose of sequence analysis. Moreover, the presence of possible noisy features can also affect the…
Assessment of nonnegative matrix factorization algorithms for electroencephalography spectral analysis.
2020
AbstractBackgroundNonnegative matrix factorization (NMF) has been successfully used for electroencephalography (EEG) spectral analysis. Since NMF was proposed in the 1990s, many adaptive algorithms have been developed. However, the performance of their use in EEG data analysis has not been fully compared. Here, we provide a comparison of four NMF algorithms in terms of accuracy of estimation, stability (repeatability of the results) and time complexity of algorithms with simulated data. In the practical application of NMF algorithms, stability plays an important role, which was an emphasis in the comparison. A Hierarchical clustering algorithm was implemented to evaluate the stability of NM…
John H. McWhorter, Linguistic simplicity and complexity: Why do languages undress? Language contact and bilingualism, Vol. 1. Berlin: De Gruyter Mout…
2013
The Syllogistic with Unity
2011
We extend the language of the classical syllogisms with the sentence-forms “At most 1 p is a q” and “More than 1 p is a q”. We show that the resulting logic does not admit a finite set of syllogism-like rules whose associated derivation relation is sound and complete, even when reductio ad absurdum is allowed.