Search results for "value"
showing 10 items of 5321 documents
Zero-range model of traffic flow.
2005
A multi--cluster model of traffic flow is studied, in which the motion of cars is described by a stochastic master equation. Assuming that the escape rate from a cluster depends only on the cluster size, the dynamics of the model is directly mapped to the mathematically well-studied zero-range process. Knowledge of the asymptotic behaviour of the transition rates for large clusters allows us to apply an established criterion for phase separation in one-dimensional driven systems. The distribution over cluster sizes in our zero-range model is given by a one--step master equation in one dimension. It provides an approximate mean--field dynamics, which, however, leads to the exact stationary s…
Non-uniform Sediment Transport Estimation in Non-equilibrium Situations: Case Studies
2014
Abstract Quantitative estimate of sediment transport in alluvial channels is one of the most important task in river engineering. Even today, numerical models of sediment transport processes are confronted with some difficulties, often of conceptual nature. One of these difficulties is the simulation of non-uniform sediment transport in non-equilibrium situations, which requires the characterization of the ability of the alluvial system to immediately overcome the variations of the sediment boundary conditions. In this work a 1-D numerical model, which includes a new expression of the so-called “adaptation coefficient”, has been applied to test its capability to simulate the transient bed p…
About the reliability, efficiency, and meaning of the error estimates of a LAOCOON3-type NMR analysis system
1977
Abstract The statistical error estimates of a LAOCOON3-type system are tested. The analyzabilities of a spectrum and spectral parameters are described by a new measure. The variation in the uncertainties of the parameters can be explained by correlation coefficients. According to the calculations made, the error estimates are normally quite reliable if the accuracy of the observed spectrum is known. In some cases the Newton-Raphson type of iteration does not converge or the confidence limits of the parameters are enormous or both; an example is discussed. It seems clear that one cannot avoid differing uncertainties of the parameters by changing the method of analysis, or that one can avoid …
The Many Faces of Interactivity in Convergent Media Environments. Assessing Uses and Effects of Interactivity from a User and Management Perspective
2013
Digitization has blurred the distinctions between producers and audiences. Thus, research on interactivity as a key element of convergent media environments has grown dramatically over the past three decades. However, despite this strong research interest there is currently no consensus about the multi-faced and hard-to-grasp concept. Obviously, interactivity is used to describe numerous processes in convergent media environments that are related to communication in general, and online communication and practices like online journalism in particular. This article highlights the main strands in the conceptual development of interactivity and explores some of the effects of interactivity by s…
Measuring Child-Rearing Values. A Research Note
2012
Abstract Large scale comparative studies, such as the value surveys (EVS and WVS) or the Eurobarometer, include measurements for parental/child-rearing values. This reflects a persistent interest for the topic, which produced salient studies starting with the first half of the twentieth century (Lynd and Lund 1929; Duvall 1946). Various scholars report data on parental values which use versions of the Q-sort methodology (Kohn 1977), ranking variables (Alwin 1990; Lenski 1961), scale indicators (Tulviste et al. 2007). Q-sort methodology remains the most widely employed. One of its versions is included in the value surveys as well. However, it fails to produce comparable indicators in differe…
Exact constants in Poincaré type inequalities for functions with zero mean boundary traces
2014
In this paper, we investigate Poincare type inequalities for the functions having zero mean value on the whole boundary of a Lipschitz domain or on a measurable part of the boundary. We find exact and easily computable constants in these inequalities for some basic domains (rectangles, cubes, and right triangles) and discuss applications of the inequalities to quantitative analysis of partial differential equations. Copyright © 2014 John Wiley & Sons, Ltd.
A Shock to the System: HIV among Older African Women in Zimbabwe
2018
HIV remains a threat to the ordinary everyday life of older woman in African society. In what can be called “a reality shock,” HIV challenges most of the ordinary everyday endeavors in conservative African societies as it imposes new Western prevention, treatment, and health-management methods over long-held African traditions. The reality of the “Western” HIV epidemic, and its impact on the “African” ordinary everyday life, demands that the infected undergo a paradigm shift in order for them to live harmoniously within their society. This calls for a re-examination of traditional values and a strong sense of responsibility, courage, and determination to remain relevant and not be considere…
The 'power' of tourism in Portugal
2012
The author analyses the upper tail of the distribution of tourism supply in Portugal from 2002 to 2009, using data from the Instituto Nacional de Estatística database. Tourism supply is defined in terms of the lodging capacity of hotel establishments in about 250 tourist destinations. The paper shows that the empirical distribution of tourism supply in Portugal is heavy-tailed and consistent with a power law behaviour in its upper tail. Such behaviour seems to be stable over the years, provided that, for the time horizon covered by the data sets, the scaling parameter is always close to the value of two. The power law hypothesis is tested positively through the use of graphical and analyti…
Noise estimation from digital step-model signal
2013
International audience; This paper addresses the noise estimation in the digital domain and proposes a noise estimator based on the step signal model. It is efficient for any distribution of noise because it does not rely only on the smallest amplitudes in the signal or image. The proposed approach uses polarized/directional derivatives and a nonlinear combination of these derivatives to estimate the noise distribution (e.g., Gaussian, Poisson, speckle, etc.). The moments of this measured distribution can be computed and are also calculated theoretically on the basis of noise distribution models. The 1D performances are detailed, and as our work is mostly dedicated to image processing, a 2D…
Interior Eigenvalue Density of Jordan Matrices with Random Perturbations
2017
International audience; We study the eigenvalue distribution of a large Jordan block subject to a small random Gaussian perturbation. A result by E. B. Davies and M. Hager shows that as the dimension of the matrix gets large, with probability close to 1, most of the eigenvalues are close to a circle.We study the expected eigenvalue density of the perturbed Jordan block in the interior of that circle and give a precise asymptotic description.; Nous étudions la distribution de valeurs propres d’un grand bloc de Jordan soumis à une petite perturbation gaussienne aléatoire. Un résultat de E. B. Davies et M. Hager montre que quand la dimension de la matrice devient grande, alors avec probabilité…