Search results for "variance"
showing 10 items of 2030 documents
Variances as order parameter and complexity measure for random Boolean networks
2005
Several order parameters have been considered to predict and characterize the transition between ordered and disordered phases in random Boolean networks, such as the Hamming distance between replicas or the stable core, which have been successfully used. In this work, we propose a natural and clear new order parameter: the temporal variance. We compute its value analytically and compare it with the results of numerical experiments. Finally, we propose a complexity measure based on the compromise between temporal and spatial variances. This new order parameter and its related complexity measure can be easily applied to other complex systems.
Annealed Invariance Principle for Random Walks on Random Graphs Generated by Point Processes in R-d
2016
International audience; We consider simple random walks on random graphs embedded in R-d and generated by point processes such as Delaunay triangulations, Gabriel graphs and the creek-crossing graphs. Under suitable assumptions on the point process, we show an annealed invariance principle for these random walks. These results hold for a large variety of point processes including Poisson point processes, Matern cluster and Matern hardcore processes which have respectively clustering and repulsiveness properties. The proof relies on the use the process of the environment seen from the particle. It allows to reconstruct the original process as an additive functional of a Markovian process und…
Covarying shell growth parameters and the regulation of shell shape in marine bivalves: a case study on Tellinoidea.
2014
Specific parameters characterising shell shape may arguably have a significant role in the adaptation of bivalve molluscs to their particular environments. Yet, suchfunctionally relevantshape parameters (shell outline elongation, dissymmetry, and ventral convexity) are not those parameters that the animal may directly control. Rather than shell shape, the animal regulates shell growth. Accordingly, an alternative,growth-baseddescription of shell-shape is best fitted to understand how the animal may control the achieved shell shape. The key point is, in practice, to bring out the link between those two alternative modes of shell-shape descriptions, that is, to derive the set of equations whi…
Hemispheric asymmetry in the visual contribution to postural control in healthy adults.
1997
International audience; This study was carried out in order to test the hypothesis of a right hemisphere dominance in the visual control of body balance. Eight healthy adults were subjected to a self-regulated lateral balance task, performed while sitting on a rocking platform. Four visual conditions were tested: open eyes with normal vision, closed eyes in the dark, left visual field-right hemisphere and right visual field-left hemisphere. Head and support displacements in the roll plane were recorded by means of an optoelectronic system. Two main results emerged from this study: (1) head stabilization in space was much more efficient in the left visual field-right hemisphere condition tha…
Using of a uncertainty model of an polyarticulated coordinates measuring arm to validate the measurement in a manufacturing processsus
2014
International audience; Coordinates Measuring Arms (CMA) are increasingly used to control industrial parts and are often an alternative to CMM controls that require conditions of laboratory measurement and involve significant costs. However, the control of uncertainties is often not guaranteed because the measurement process is complex and there is no standard for setting a framework qualification process of the measurement process.The proposed study, in this paper, is a first approach to model the measurement uncertainties of a CMA with contact sensor. The problem is complex because there are many sources of uncertainty, largely due to variability in the handling carried out by the operato…
Calcul des contributions des incertitudes dans un modèle complexe de qualité de l'eau
2010
The quantification of uncertainty in integrated urban drainage water quality models is of paramount interest. Indeed, the assessment of the reliability of the model results for complex water quality models is useful for understanding the significance of the results. However, the state of knowledge regarding uncertainties in urban drainage models is poor. In the case of integrated urban drainage water quality models, due to the fact that integrated approaches are basically a cascade of sub-models (simulating sewer system, wastewater treatment plant and receiving water body), the uncertainty produced in one sub-model propagates to the following ones depending on the model structure, the estim…
Seuil de détection d'une population, détermination par la méthode du modèle linéaire généralisé
1997
National audience
CAP : Une méthode et un outil de contrôle rapide et synthétique des performances des sujets en évaluation sensorielle descriptive
1997
National audience
Exploring the deviations from scale-invariance of spatial distributions of buildings using a Geographically Weighted Fractal Analysis. An application…
2018
In the early twentieth century a handful of French geographers and historians famously suggested that mainland France comprised two agrarian systems: enclosed field systems with scattered settlements in the central and western France, and openfield systems with grouped settlements in eastern France. This division between grouped and scattered settlements can still be found on the outskirts of urban areas. The objective of this paper is to determine whether the shape of urban areas varies with the type of built patterns in their periphery. To this end, we identify and characterise the local and global deviations from scale-invariance of built patterns in metropolitan France. We propose a new…
Intérêts et apports de l'analyse des variables latentes pour le chercheur en sciences sociales : exemple d'application à l'économie de l'éducation
2002
The ambition of this article is modest. Initially, it aims at presenting in a sample manner the concepts that underpin the standard use of LISREL models and showing their usefulness in social science research. It then proposes, as an illustration of the theoretical presentation, an example of application relating to the use of school time in the education system.