Search results for "emergence"
showing 10 items of 56 documents
Spin-1/2 sub-dynamics nested in the quantum dynamics of two coupled qutrits
2017
In this paper we investigate the quantum dynamics of two spin-1 systems, $\vec{\textbf{S}}_1$ and $\vec{\textbf{S}}_2$, adopting a generalized $(\vec{\textbf{S}}_1+\vec{\textbf{S}}_2)^2$-nonconserving Heisenberg model. We show that, due to its symmetry property, the nine-dimensional dynamics of the two qutrits exactly decouples into the direct sum of two sub-dynamics living in two orthogonal four- and five-dimensional subspaces. Such a reduction is further strengthened by our central result consisting in the fact that in the four-dimensional dynamically invariant subspace, the two qutrits quantum dynamics, with no approximations, is equivalent to that of two non interacting spin 1/2's. The …
Interactive Effects of Explicit Emergent Structure: A Major Challenge for Cognitive Computational Modeling
2015
International audience; David Marr's (1982) three-level analysis of computational cognition argues for three distinct levels of cognitive information processingnamely, the computational, representational, and implementational levels. But Marr's levels areand were meant to bedescriptive, rather than interactive and dynamic. For this reason, we suggest that, had Marr been writing today, he might well have gone even farther in his analysis, including the emergence of structurein particular, explicit structure at the conceptual levelfrom lower levels, and the effect of explicit emergent structures on the level (or levels) that gave rise to them. The message is that today's cognitive scientists …
Individual Decisions and Perceived Form in Collective Free Improvisation
2015
International audience; This paper proposes a first attempt to study quantitatively Collective Free Improvisation (CFI). We report an experiment designed to study the relationship between the improvisers’ individual high-level decisions and the improvisation’s form perceived by external auditors. We recorded 16 trios in which the improvisers used a MIDI-pedal to indicate in real-time a significant change in their own musical production. Expert listeners were later asked to segment each improvisation so that we obtained their perception of the structure. By analysing the correlations between musicians’ individual decisions and listeners’ segmentation points, we discuss how the improvisation’…
Weed seeds ability to emerge on the soil surface
2015
International audience; Annual weeds have to produce seeds each year to maintain their populations. These seeds fallon the soil surface. Seeds exposed to light during their moistening (i.e. caused by rain) bettergerminate than seeds in the darkness (i.e. buried). However, rare studies quantified the unique andcombined effects of light, moisture and burial depth on the germination process. We investigated,in a greenhouse experiment in 2014, the impact of seed moisture (Moistened vs. Dried), lightduring moistening (Darkness vs. Light) and burial depth (Buried vs. Surface) on germination of 12annual weed species contrasted on their seed traits and germination periods (Alopecurusmyosuroides Hud…
Importance of seeds in the process of common ragweed invasion
2012
International audience; Ambrosia artemisiifolia L. (common ragweed) was introduced into Europe at the end of the 1900s and is now present in several European countries. This annual invasive plant produces seeds that are highly polymorphic. Common ragweed can produce only a few thousand highly viable seeds. Many studies have focused on the seed stage. Greater seedling emergence for the seeds placed near the soil surface could explain the success of this species in open habitats, where the probability of deeper burial is low. Emergence percentage was found to decrease as burial depth increased from 2 to 8 cm, and no germination nor seedling emergence was observed for the seeds buried from 10-…
SYSTEM DYNAMICS VERSUS CELLULAR AUTOMATA IN MODELLING PANIC SITUATIONS
2008
International audience; In this paper we face system dynamics modelling and cellular automata to model panic processes. We compare both models using phase plans. The results of simulation confirm our hypotheses: First, a collective behaviour is not the arithmetical sum of the individual behaviours. Secondly the crowd causes the emergence of collective panic from individual panic. Both types of methodology produce the emergence of panic and identical curves for different values of initial conditions and parameters. But the effects of thresholds vary according to these values.
Emergence of feeling in osteopathic manual listening
2014
International audience
The influence of infective dose, nutrient availability and coinfection on virulence of Flavobacterium columnare : implications of intensive aquacultu…
2016
Ecological factors are known to affect disease dynamics and even lead to disease emergence. Especially in opportunistic, environmentally transmitted pathogens, the environment may significantly contribute to pathogen virulence. Intensive farming, including aquaculture, has been suggested to create conditions favouring development of highly virulent pathogens. At Finnish fish farms, epidemics caused by opportunistic Flavobacterium columnare have been constantly increasing in their prevalence and severity since the 1980’s. Yet, factors behind the increased virulence of the pathogen and their mechanisms of action have largely remained unsolved. In this thesis, I explore the effects of infectio…
Effective charge from lattice QCD
2020
Using lattice configurations for quantum chromodynamics (QCD) generated with three domain-wall fermions at a physical pion mass, we obtain a parameter-free prediction of QCD's renormalisation-group-invariant process-independent effective charge, $\hat\alpha(k^2)$. Owing to the dynamical breaking of scale invariance, evident in the emergence of a gluon mass-scale, this coupling saturates at infrared momenta: $\hat\alpha(0)/\pi=0.97(4)$. Amongst other things: $\hat\alpha(k^2)$ is almost identical to the process-dependent (PD) effective charge defined via the Bjorken sum rule; and also that PD charge which, employed in the one-loop evolution equations, delivers agreement between pion parton di…
Between models and narratives: transitions in settlement systems
2021
International audience