373 research outputs found
D2.2 Needs assessment for future professional training in Europe
The document presents a qualitative view of the e-learning market in companies, and above all, to determine precisely the customer needs on that market in the near futureEuropean Commission, through the FP-5 IST programm
D2.1 Overview of the current and emerging European Professional Training Market
Present developments and trends in the European (e)training market for professionals. Includes an overview by regions and description of the major players.European Commission, through the FP-5 IST programm
Finite size scaling of current fluctuations in the totally asymmetric exclusion process
We study the fluctuations of the current J(t) of the totally asymmetric
exclusion process with open boundaries. Using a density matrix renormalization
group approach, we calculate the cumulant generating function of the current.
This function can be interpreted as a free energy for an ensemble in which
histories are weighted by exp(-sJ(t)). We show that in this ensemble the model
has a first order space-time phase transition at s=0. We numerically determine
the finite size scaling of the cumulant generating function near this phase
transition, both in the non-equilibrium steady state and for large times.Comment: 18 pages, 11 figure
Leertechnologie in de lage landen
Op het terrein van onderwijs en ICT investeren onderwijsinstellingen, bedrijven, brancheorganisaties en overheden in het bewerkstelligen van leertechnologie-afspraken. Het doel van die gezamenlijke inspanning is om het onderwijs te kunnen verbeteren en efficiënter te maken. Gedeelde opvattingen, vastgelegd in specificaties en standaarden, maken uitwisseling van gegevens mogelijk tussen uiteenlopende systemen. Dat biedt grote kansen voor onderwijsvernieuwing. Basisgegevens hoeven slechts op één plek onderhouden te worden, maar zijn toch voor iedere instelling bruikbaar: eenmaal gemaakte lesmaterialen kunnen in verschillende leeromgevingen worden ingezet, studenten kunnen zich flexibel inschrijven voor cursussen aan verschillende instellingen terwijl hun studievoortgang zonder probleem wordt geregistreerd. Deze processen zijn essentiële voorwaarden voor een duurzame ontwikkeling van e-learning in de Lage Landen.
Als samenwerkingsorganisatie voor het hoger onderwijs in Nederland neemt SURF deel aan de mars naar standaardisatie binnen de leertechnologie. De SURF SiX expertisegroep, een Special Interest Group van SURF, onderneemt activiteiten om realisatie en gebruik van leertechnologie-afspraken te bevorderen die voor het Nederlandse hoger onderwijs bruikbaar en nuttig zijn en die blijvende aansluiting van Nederland bij internationale e-learningontwikkelingen garanderen. Met dit boek geeft SURF SiX een brede groep onderwijsontwikkelaars en geĂŻnformeerde eindgebruikers inzicht in de huidige Nederlandse situatie op het gebied van leertechnologie-afspraken. Daarnaast wil dit boek laten zien dat leertechnologiespecificaties en standaarden meerwaarde hebben.Stichting Sur
Thermodynamics of histories for the one-dimensional contact process
The dynamical activity K(t) of a stochastic process is the number of times it
changes configuration up to time t. It was recently argued that (spin) glasses
are at a first order dynamical transition where histories of low and high
activity coexist. We study this transition in the one-dimensional contact
process by weighting its histories by exp(sK(t)). We determine the phase
diagram and the critical exponents of this model using a recently developed
approach to the thermodynamics of histories that is based on the density matrix
renormalisation group. We find that for every value of the infection rate,
there is a phase transition at a critical value of s. Near the absorbing state
phase transition of the contact process, the generating function of the
activity shows a scaling behavior similar to that of the free energy in an
equilibrium system near criticality.Comment: 16 pages, 7 figure
Comparison of Stochastic Methods for the Variability Assessment of Technology Parameters
This paper provides and compares two alternative solutions for the simulation of cables and interconnects with the inclusion of the effects of parameter uncertainties, namely the Polynomial Chaos (PC) method and the Response Surface Modeling (RSM). The problem formulation applies to the telegraphers equations with stochastic coefficients. According to PC, the solution requires an expansion of the unknown parameters in terms of orthogonal polynomials of random variables. On the contrary, RSM is based on a least-square polynomial fitting of the system response. The proposed methods offer accuracy and improved efficiency in computing the parameter variability effects on system responses with respect to the conventional Monte Carlo approach. These approaches are validated by means of the application to the stochastic analysis of a commercial multiconductor flat cable. This analysis allows us to highlight the respective advantages and disadvantages of the presented method
A Fuzzy Hybrid Sequential Design Strategy for Global Surrogate Modeling of High-Dimensional Computer Experiments
Dredging fundamentally reshapes the ecological significance of 3D terrain features for fish in estuarine seascapes
Context: Landscape modification alters the condition of ecosystems and the structure of terrain, with widespread impacts on biodiversity and ecosystem functioning. Seafloor dredging impacts a diversity of flora and fauna in many coastal landscapes, and these processes also transform three-dimensional terrain features. The potential ecological significance of these terrain changes in urban seascapes has, however, not been investigated.
Objectives: We examined the effects of terrain variation on fish assemblages in 29 estuaries in eastern Australia, and tested whether dredging changes how fish associate with terrain features.
Methods: We surveyed fish assemblages with baited remote underwater video stations and quantified terrain variation with nine complementary metrics (e.g. depth, aspect, curvature, slope, roughness), extracted from bathymetry maps created with multi-beam sonar.
Results: Fish diversity and abundance were strongly linked to seafloor terrain in both natural and dredged estuaries, and were highest in shallow waters and near features with high curvature. Dredging, however, significantly altered the terrain of dredged estuaries and transformed the significance of terrain features for fish assemblages. Abundance and diversity switched from being correlated with lower roughness and steeper slopes in natural estuaries to being linked to features with higher roughness and gentler slopes in dredged estuaries.
Conclusions: Contrasting fish-terrain relationships highlight previously unrecognised ecological impacts of dredging, but indicate that plasticity in terrain use might be characteristic of assemblages in urban landscapes. Incorporating terrain features into spatial conservation planning might help to improve management outcomes, but we suggest that different approaches would be needed in natural and modified landscapes
Seafloor Terrain Shapes the Three-dimensional Nursery Value of Mangrove and Seagrass Habitats
Mangroves and seagrasses are important nurseries for many marine species, and this function is linked to the complexity and context of these habitats in coastal seascapes. It is also connected to bathymetric features that influence habitat availability, and the accessibility of refuge habitats, but the significance of terrain variation for nursery function is unknown. To test whether seafloor terrain influences nursery function, we surveyed fish assemblages from mangrove and seagrass habitats in 29 estuaries in eastern Australia with unbaited underwater cameras and quantified the surrounding three-dimensional terrain with a set of complementary surface metrics (that is, depth, aspect, curvature, slope, roughness) applied to sonar-derived bathymetric maps. Terrain metrics explained variability in assemblages in both mangroves and seagrasses, with differing effects for the entire fish assemblage and nursery species composition, and between habitats. Higher depth, plan curvature (concavity or convexity) and roughness (backscatter) were negatively correlated with abundance and diversity in mangroves and positively linked to abundance and diversity in seagrass. Mangrove nursery species (6 species) were most abundant in forests adjacent to flats with concave holes, rough substrates and low-moderate depths, whereas seagrass nursery species (3 species) were most abundant in meadows adjacent to deep channels with soft mounds and ledges. These findings indicate that seafloor terrain influences nursery function and demonstrate contrasting effects of terrain variation in mangroves and seagrass. We suggest that incorporating three-dimensional terrain into coastal conservation and restoration plans could help to improve outcomes for fisheries management, but contrasting strategies might be needed for different nursery habitats
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