Search results for "Statistical"

Information Decomposition in Bivariate Systems: Theory and Application to Cardiorespiratory Dynamics

2015

In the framework of information dynamics, the temporal evolution of coupled systems can be studied by decomposing the predictive information about an assigned target system into amounts quantifying the information stored inside the system and the information transferred to it. While information storage and transfer are computed through the known self-entropy (SE) and transfer entropy (TE), an alternative decomposition evidences the so-called cross entropy (CE) and conditional SE (cSE), quantifying the cross information and internal information of the target system, respectively. This study presents a thorough evaluation of SE, TE, CE and cSE as quantities related to the causal statistical s…

Les études hédoniques soutiennent-elles une valeur verte élevée dans le bâtiment ? Une réponse par la méta-analyse

2018

International audience; La place majeure occupée par le secteur du bâtiment dans la consommation d'énergie (40%) et les émissions de gaz à effet de serre (1/3 des émissions) explique le développement du débat scientifique axé sur la réduction de l'impact environnemental du bâtit et sur ses leviers. Ces dernières années ont notamment vu croitre une littérature considérable relative à la disposition à payer du public pour les bâtiments « verts » labélisés par des écolabels, cette « valeur verte » étant estimée dans la grande majorité des études via des modèles hédoniques. Dans cet article, nous proposons d'offrir une synthèse de ces résultats dans le cadre d'une méta-analyse portant sur plus …

Bulk and interfacial properties in colloid-polymer mixtures

2005

Large-scale Monte Carlo simulations of a phase-separating colloid-polymer mixture are performed and compared to recent experiments. The approach is based on effective interaction potentials in which the central monomers of self-avoiding polymer chains are used as effective coordinates. By incorporating polymer nonideality together with soft colloid-polymer repulsion, the predicted binodal is in excellent agreement with recent experiments. In addition, the interfacial tension as well as the capillary length are in quantitative agreement with experimental results obtained at a number of points in the phase-coexistence region, without the use of any fit parameters.

Interfaces between coexisting phases of polymer mixtures: Comparison between Monte Carlo simulations and theoretical predictions

1997

Large scale Monte Carlo investigations of the interface between A-rich and B-rich phases of symmetric binary (AB) polymer mixtures are presented, using the bond fluctuation model of flexible chains with NA=NB=N=32 effective monomers. The temperature range studied, 0.144<T/Tc0.759, includes both the strong and the weak segregation limit. Interfacial free energy and interfacial structure are studied, and compared to predictions based on the selfconsistent field theory. Also the broadening of the interfacial width due to capillary waves is considered, and finite size effects due to the confinement of interfaces in thin films of polymer blends are discussed.

Static properties of end-tethered polymers in good solution: A comparison between different models

2004

We present a comparison between results, obtained from different simulation models, for the static properties of end-tethered polymer layers in good solvent. Our analysis includes data from two previous studies--the bond fluctuation model of Wittmer et al. [J. Chem. Phys. 101, 4379 (1994)] and the off-lattice bead-spring model of Grest and Murat [Macromolecules 26, 3108 (1993)]. Additionally, we explore the properties of a similar off-lattice model simulated close to the Theta temperature. We show that the data for the bond fluctuation and the Grest-Murat model can be analyzed in terms of scaling theory because chains are swollen inside the Pincus blob. In the vicinity of the Theta point th…

Dynamics of confined polymer melts: Recent Monte Carlo simulation results

2000

The dynamic behavior of thin polymer films is studied by Monte Carlo simulations of a simplified lattice model. The film geometry is realized by two opposite hard walls whose distance is varied in the simulations. In the films the dynamics is accelerated with respect to the bulk, leading to a decrease of the extrapolated glass transition temperature with decreasing film thickness.

Heterogeneity at the glass transition: a review

1999

Theoretical concepts and experimental evidence of heterogeneity in glass-forming liquids and polymers are reviewed. The main purpose is to provide an introduction to theoretical developments and recent experiments which have led to rapidly increasing knowledge. Realizing that there is no consensus in regard to the various scenarios of the glass transition starting from rather different assumptions we try to give a balanced overview although we also compare and interrelate some of the approaches. The experimental part describes recent nuclear magnetic resonance, dielectric, and optical experiments from which dynamically distinguishable subensembles can be selected thus proving the existence …

Direct evaluation of the electron density correlation function of partially crystalline polymers

1980

A discussion of the general properties of the one-dimensional electron density correlation function K(z) of a partially crystalline polymer with lamellar structure shows that application of a graphical extrapolation procedure permits direct determination of the crystallinity, the specific inner surface, and the electron density difference ηc − ηa. The procedure is based upon the occurrence of a straight section in the “self-correlation” range of K(z). Curved and nonparallel lamellae do not invalidate the concept. In the case of heterogeneous samples composed of partially crystalline and totally amorphous regions, some of the parameters of the experimentally obtained correlation function, as…

Statistical Mechanics of Polymers: New Developments - International Workshop

2007

Mechanical behaviour of Mater-Bi/wood flour composites: a statistical approach

2008

Interest in biocomposites (lignocellulosic filled biopolymers) started in the 90s, due to environmental advantages, related to the full biodegradability of both matrix and filler, economical issues (organic fillers usually come from sawmill or agriculture wastes) and aesthetical issues (wood filled biopolymers could be particularly pleasant if used for indoor furnishing and automotive interior). In this work, a method for a systematic study of the properties of Mater-Bi®/wood flour composites is presented. A two-level full factorial model was built. It allows investigating the effects of multiple operative variables on the observed properties, their contributions, their optimal combinations…