865 resultados para diffusion of information
Resumo:
We introduce two ways of comparing information structures, say ${\cal I}$ and${\cal J}$. First we say that ${\cal I}$ is richer than ${\cal J}$ when forevery compact game $G$, all correlated equilibrium distributions of $G$ inducedby ${\cal J}$ are also induced by ${\cal I}$. Second, we say that ${\cal J}$is faithfully reproducable from ${\cal I}$ when all the players can computefrom their information in ${\cal I}$ ``new information'' that they could havereceived from ${\cal J}$. We prove that ${\cal I}$ is richer than ${\cal J}$if and only if ${\cal J}$ is faithfully reproducable from ${\cal I}$.
Resumo:
Qualsevol professió té, o hauria de tenir, un codi de regles ètiques que els seus membres normalment respecten i que fan servir com a guia en el cas que hagin de prendre decisions moralment difícils. Durant la reunió celebrada el novembre de 1998 a Lisboa, les associacions membres de l'ECIA van acordar adoptar un codi ètic que fos vàlid per als professionals de tots els països de la Unió Europea. Aquest codi no pot ser més que un enunciat de principis generals i deixa en mans de cada associació la facultat de desenvolupar-lo per tal que respongui a necessitats especials o nacionals. Un primer projecte fou presentat i discutit a la reunió de l'ECIA de març de 1999. La present revisió incorpora les modificacions proposades aleshores, elements provinents de codis d'altres organitzacions que foren presentats en la reunió a la consideració de l'autor, així com alguns aclariments.
Resumo:
A simple model for a dimer molecular diffusion on a crystalline surface, as a function of temperature, is presented. The dimer is formed by two particles coupled by a quadratic potential. The dimer diffusion is modeled by an overdamped Langevin equation in the presence of a two-dimensional periodic potential. Numerical simulation¿s results exhibit some dynamical properties observed, for example, in Si2 diffusion on a silicon [100] surface. They can be used to predict the value of the effective friction parameter. Comparison between our model and experimental measurements is presented.
Resumo:
The diffusion of passive scalars convected by turbulent flows is addressed here. A practical procedure to obtain stochastic velocity fields with well¿defined energy spectrum functions is also presented. Analytical results are derived, based on the use of stochastic differential equations, where the basic hypothesis involved refers to a rapidly decaying turbulence. These predictions are favorable compared with direct computer simulations of stochastic differential equations containing multiplicative space¿time correlated noise.
Resumo:
To evaluate primary care physicians' attitude towards implementation of rotavirus (RV) immunisation into the Swiss immunisation schedule, an eight-question internet-based questionnaire was sent to the 3799 subscribers of InfoVac, a nationwide web-based expert network on immunisation issues, which reaches >95% of paediatricians and smaller proportions of other primary care physicians. Five demographic variables were also inquired. Descriptive statistics and multivariate analyses for the main outcome "acceptance of routine RV immunisation" and other variables were performed. Diffusion of innovation theory was used for data assessment. Nine-hundred seventy-seven questionnaires were returned (26%). Fifty percent of participants were paediatricians. Routine RV immunisation was supported by 146 participants (15%; so called early adopters), dismissed by 620 (64%), leaving 211 (21%) undecided. However, when asked whether they would recommend RV vaccination to parents if it were officially recommended by the federal authorities and reimbursed, 467 (48.5%; so called early majority) agreed to recommend RV immunisation. Multivariate analysis revealed that physicians who would immunise their own child (OR: 5.1; 95% CI: 4.1-6.3), hospital-based physicians (OR: 1.6; 95% CI: 1.1-2.3) and physicians from the French (OR: 1.6; 95% CI: 1.2-2.3) and Italian speaking areas of Switzerland (OR: 2.5; 95% CI: 1.1-5.8) were more likely to support RV immunisation. Diffusion of innovation theory predicts a >80% implementation if approximately 50% of a given population support an innovation. Introduction of RV immunisation in Switzerland is likely to be successful, if (i) the federal authorities issue an official recommendation and (ii) costs are covered by basic health care insurance.
Resumo:
This document produced by the Iowa Department of Administrative Services has been developed to provide a multitude of information about executive branch agencies/department on a single sheet of paper. The facts provides general information, contact information, workforce data, leave and benefits information and affirmative action data.
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We present a procedure for the optical characterization of thin-film stacks from spectrophotometric data. The procedure overcomes the intrinsic limitations arising in the numerical determination of manyparameters from reflectance or transmittance spectra measurements. The key point is to use all theinformation available from the manufacturing process in a single global optimization process. The method is illustrated by a case study of solgel applications.
Resumo:
This document produced by the Iowa Department of Administrative Services has been developed to provide a multitude of information about executive branch agencies/department on a single sheet of paper. The facts provides general information, contact information, workforce data, leave and benefits information and affirmative action data.
Resumo:
The diffusion of passive scalars convected by turbulent flows is addressed here. A practical procedure to obtain stochastic velocity fields with well¿defined energy spectrum functions is also presented. Analytical results are derived, based on the use of stochastic differential equations, where the basic hypothesis involved refers to a rapidly decaying turbulence. These predictions are favorable compared with direct computer simulations of stochastic differential equations containing multiplicative space¿time correlated noise.
Resumo:
The fate of European arctic-alpine species during Pleistocene climatic oscillations still remains debated. Did these cold-adapted species invade much of the continental steppe or did they remain restricted to warmer slopes of inner mountain massifs? To examine this question, we investigated the phylogeography of Gentiana nivalis, a typical European arctic-alpine plant species. Genome fingerprinting analyses revealed that four genetic pools are actually unevenly distributed across the continent. One cluster covers almost all mountain massifs as well as northern areas, and thus coincides with a scenario of past distribution covering a large part of the European glacial steppe. In contrast, the three other lineages are strongly restricted spatially to western, central, and eastern Alps, respectively, thus arguing towards a scenario of in situ glacial survival. The coexistence of lineages with such contrasting demographic histories in Europe challenges our classical view of refugia and corroborates several hypotheses of biogeographers from the twentieth century.
Resumo:
The influenza of the winter of 1889-90 was one of the first epidemics to spread all over the world. At the time, several people hypothesized that the railway was one of the main vectors of diffusion of this influenza. This hypothesis was defended in Switzerland especially by Schmid, Chief of the Swiss Office of Health, who collected an impressive body of material about the spread of the epidemic in that country. These data on influenza combined with data about the structure of the railway are used in this paper in order to test the hypothesis of a mixed diffusion process, first between communes interconnected by the railway, and secondly, between those communes and neighbouring communes. An event history analysis model taking into account diffusion effects is proposed and estimated. Results show that the hypothesis is supported if the railway network in Switzerland is not taken as a whole but if a distinction between railway companies is made.