36,696 research outputs found
Networked by design: can policy constraints support the development of capabilities for collaborative innovation?
While there has been some recent interest in the behavioural effects of policies in support of innovation networks, this research field is still relatively new. In particular, an important but under-researched question for policy design is “what kind of networks” should be supported, if the objective of the policy is not just to fund successful innovation projects, but also to stimulate behavioural changes in the participants, such as increasing their ability to engage in collaborative innovation. By studying the case of the innovation policy programmes implemented by the regional government of Tuscany, in Italy, between 2002 and 2008, we assess whether the imposition of constraints on the design of innovation networks has enhanced the participants’ collaborative innovation capabilities, and we draw some general implications for policy
Remarks on the tensor degree of finite groups
The present paper is a note on the tensor degree of finite groups, introduced
recently in literature. This numerical invariant generalizes the commutativity
degree through the notion of nonabelian tensor square. We show two
inequalities, which correlate the tensor and the commutativity degree of finite
groups, and, indirectly, structural properties will be discussed.Comment: 5 pages; to appear with revisions in Filoma
Security policy refinement using data integration: a position paper.
In spite of the wide adoption of policy-based approaches for security management, and many existing treatments of policy verification and analysis, relatively little attention has been paid to policy refinement: the problem of deriving lower-level, runnable policies from higher-level policies, policy goals, and specifications. In this paper we present our initial ideas on this task, using and adapting concepts from data integration. We take a view of policies as governing the performance of an action on a target by a subject, possibly with certain conditions. Transformation rules are applied to these components of a policy in a structured way, in order to translate the policy into more refined terms; the transformation rules we use are similar to those of global-as-view database schema mappings, or to extensions thereof. We illustrate our ideas with an example. Copyright 2009 ACM
Universality and Scaling at the Onset of Quantum Black Hole Formation
In certain two-dimensional models, collapsing matter forms a black hole if
and only if the incoming energy flux exceeds the Hawking radiation rate. Near
the critical threshold, the black hole mass is given by a universal formula in
terms of the distance from criticality, and there exists a scaling solution
describing the formation and evaporation of an arbitrarily small black hole.Comment: 9 pages, 3 figures (uuencoded
Low Energy Action of "Covariant" Superstring Field Theory in the NS-NS pp-Wave Background
Exact construction of superstring field theory in some background fields is
very important. We construct the low energy NS-NS sector of superstring field
action in the pp-wave background with the flux of NS-NS antisymmetric tensor
field (NS-NS pp-wave) without gauge fixing up to the second-order where the
action is world-sheet BRST invariant. Here we use the word "covariant" in a
invariant theory for a symmetric transformation of the pp-wave background which
is not the Lorentz transformation in the flat background. Moreover we prove the
exact correspondence between this low energy action and the second-order
perturbation of supergravity action in the same background. We also prove the
correspondence of the gauge transformation in both the actions. This
construction is based on the BRST first quantization of superstrings in the
pp-wave background in our previous paper.Comment: 34 page
Mandatory vaccinations in European countries, undocumented information, false news and the impact on vaccination uptake: the position of the Italian pediatric society.
BACKGROUND: High rates of vaccination coverage are important in preventing infectious diseases. Enforcing mandatory vaccinations is one of the strategies that some Countries adopted to protect the community when vaccination coverage is not satisfactory. In Italy, in 2017 vaccination against diphtheria, tetanus, pertussis, hepatitis B, poliovirus, Haemophilus influenzae type b, measles, mumps, rubella and varicella became compulsory in childhood. In order to contrast vaccination policies, anti-vaccination campaigns contribute to the spread of fake news. Among them, there is the false information that Italy is the only one country with mandatory vaccination policy. Aim of our study is confronting vaccination policies in children under 18 months against among different European countries for the following vaccines: diphtheria, tetanus, pertussis, hepatitis B, poliovirus, Haemophilus influenzae type b, measles, mumps, rubella and varicella. METHODS: Information on policies of mandatory or recommended vaccinations of the European Countries were gathered by ECDC and compared to the Italian one. RESULTS: European Countries recommend or contemplate compulsory vaccines. Among them, eleven Countries (35.4%) have mandatory vaccinations for at least one out of diphtheria, tetanus, pertussis, hepatitis B, poliovirus, Haemophilus influenzae type b, measles, mumps, rubella and varicella vaccine. CONCLUSION: Not only in Italy, vaccination against diphtheria, tetanus, pertussis, hepatitis B, poliovirus, Haemophilus influenzae type b, measles, mumps, rubella and varicella is mandatory in children under 18 months. Other European countries adopted compulsory policies in order to prevent the spread of infectious diseases and to protect the community
Adaptive Mesh Refinement for Hyperbolic Systems based on Third-Order Compact WENO Reconstruction
In this paper we generalize to non-uniform grids of quad-tree type the
Compact WENO reconstruction of Levy, Puppo and Russo (SIAM J. Sci. Comput.,
2001), thus obtaining a truly two-dimensional non-oscillatory third order
reconstruction with a very compact stencil and that does not involve
mesh-dependent coefficients. This latter characteristic is quite valuable for
its use in h-adaptive numerical schemes, since in such schemes the coefficients
that depend on the disposition and sizes of the neighboring cells (and that are
present in many existing WENO-like reconstructions) would need to be recomputed
after every mesh adaption.
In the second part of the paper we propose a third order h-adaptive scheme
with the above-mentioned reconstruction, an explicit third order TVD
Runge-Kutta scheme and the entropy production error indicator proposed by Puppo
and Semplice (Commun. Comput. Phys., 2011). After devising some heuristics on
the choice of the parameters controlling the mesh adaption, we demonstrate with
many numerical tests that the scheme can compute numerical solution whose error
decays as , where is the average
number of cells used during the computation, even in the presence of shock
waves, by making a very effective use of h-adaptivity and the proposed third
order reconstruction.Comment: many updates to text and figure
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