Search results for " Complexity"

Almost disjoint spanning trees: relaxing the conditions for completely independent spanning trees

2017

International audience; The search of spanning trees with interesting disjunction properties has led to the introduction of edge-disjoint spanning trees, independent spanning trees and more recently completely independent spanning trees. We group together these notions by dening (i, j)-disjoint spanning trees, where i (j, respectively) is the number of vertices (edges, respectively) that are shared by more than one tree. We illustrate how (i, j)-disjoint spanning trees provide some nuances between the existence of disjoint connected dominating sets and completely independent spanning trees. We prove that determining if there exist two (i, j)-disjoint spanning trees in a graph G is NP-comple…

Ambiguity and complementation in recognizable two-dimensional languages

2008

The theory of one-dimensional (word) languages is well founded and investigated since fifties. From several years, the increasing interest for pattern recognition and image processing motivated the research on two-dimensional or picture languages, and nowadays this is a research field of great interest. A first attempt to formalize the concept of finite state recognizability for two-dimensional languages can be attributed to Blum and Hewitt ([7]) who started in 1967 the study of finite state devices that can define two-dimensional languages, with the aim to finding a counterpart of what regular languages are in one dimension. Since then, many approaches have been presented in the literature…

A two-armed bandit collective for hierarchical examplar based mining of frequent itemsets with applications to intrusion detection

2014

Published version of a chapter in the book: Transactions on Computational Collective Intelligence XIV. Also available from the publisher at: http://dx.doi.org/10.1007/978-3-662-44509-9_1 In this paper we address the above problem by posing frequent item-set mining as a collection of interrelated two-armed bandit problems. We seek to find itemsets that frequently appear as subsets in a stream of itemsets, with the frequency being constrained to support granularity requirements. Starting from a randomly or manually selected examplar itemset, a collective of Tsetlin automata based two-armed bandit players - one automaton for each item in the examplar - learns which items should be included in …

Decidability Frontier for Fragments of First-Order Logic with Transitivity

2018

Several decidable fragments of first-order logic have been identified in the past as a generalisation of the standard translation of modal logic. These include: the fluted fragment, the two-variable frag- ment, the guarded fragment and the unary negation fragment; some of them have been recently generalised or combined to yield even more expressive decidable logics (guarded negation fragment or uniform one- dimensional fragment). None of the fragments allows one to express tran- sitivity of a binary relation or related properties like being an equivalence, a linear or a partial order, that naturally appear in specifications or in verification. The question therefore arises what is the impac…

Determinants of employee well-being in project work

2021

Projects are supposed to foster innovation and flexibility and to create better conditions for learning. Accordingly, project work usually has a positive connotation for both, firms and the individ...

Route to chaos in the weakly stratified Kolmogorov flow

2019

We consider a two-dimensional fluid exposed to Kolmogorov’s forcing cos(ny) and heated from above. The stabilizing effects of temperature are taken into account using the Boussinesq approximation. The fluid with no temperature stratification has been widely studied and, although relying on strong simplifications, it is considered an important tool for the theoretical and experimental study of transition to turbulence. In this paper, we are interested in the set of transitions leading the temperature stratified fluid from the laminar solution [U∝cos(ny),0, T ∝ y] to more complex states until the onset of chaotic states. We will consider Reynolds numbers 0 < Re ≤ 30, while the Richardson numb…

Contrasting structural complexity differentiate hunting strategy in an ambush apex predator.

2021

AbstractStructural complexity is known to influence prey behaviour, mortality and population structure, but the effects on predators have received less attention. We tested whether contrasting structural complexity in two newly colonised lakes (low structural complexity lake—LSC; high structural complexity—HSC) was associated with contrasting behaviour in an aquatic apex predator, Northern pike (Esox lucius; hereafter pike) present in the lakes. Behaviour of pike was studied with whole-lake acoustic telemetry tracking, supplemented by stable isotope analysis of pike prey utilization and survey fishing data on the prey fish community. Pike displayed increased activity, space use, individual …

Bi- and three-dimensional fractal analysis of the brown seaweed Gongolaria montagnei and their relationship with gastropod molluscs assemblage

2022

Habitat complexity is one of the main influences on biodiversity in marine environments, particularly in coastal areas where foundation seaweeds provide substrate for highly diverse communities. We studied the 2D and 3D fractal dimensions of Gongolaria montagnei (Fucales) over the vegetative season and examine their relationship with the abundance, species richness and morpho-functional groups of the gastropod associated. Overall, the 3D fractal analysis method used here better describes seaweeds structural complexity compared to the traditional 2D fractal analysis, as highlighted by the higher relationship with gastropod assemblage associated to the alga in terms of abundance, number of sp…

On the evaluation of image complexity: a fuzzy approach

2005

"Table 2" of "Study of Dimuon Production in Photon-Photon Collisions and Measurement of QED Photon Structure Functions at LEP"

2001

The measured QED photon structure function at Q**2 = 120 GeV for the combine SAT and STIC data.