6,334 research outputs found
Divide and conquer: resonance induced by competitive interactions
Get PDFWe study an Ising model in a network with disorder induced by the presence of
both attractive and repulsive links. This system is subjected to a subthreshold
signal, and the goal is to see how the response is enhanced for a given
fraction of repulsive links. This can model a network of spin-like neurons with
excitatory and inhibitory couplings. By means of numerical simulations and
analytical calculations we find that there is an optimal probability, such that
the coherent response is maximal
A benchmark study on identification of inelastic parameters based on deep drawing processes using pso – nelder mead hybrid approach
Get PDFOptimization techniques have been increasingly used to identification of inelastic material parameters owing to their generality. Development of robust techniques to solving this class of inverse problems has been a challenge to researchers mainly due to the nonlinear character of the problem and behaviour of the objective function. Within this framework, this work discusses application of Particle Swarm Optimization (PSO) and a PSO – Nelder Mead hybrid approach to identification of inelastic parameters based on a benchmark solution of the deep drawing process
Spatial analyses for policy evaluation of the rural world: Portuguese agriculture in the last decade
Get PDFThis paper aims to contribute to the understanding of structural land use changes that
are occurring in rural environments, by using novel methodologies related to
Geographic Information Systems (GIS). The land use change analysis developed in this
study is associated with a pre-selected set of policy issues, that is, it offers a
retrospective view of the application of the Common Agricultural Policy (CAP) for the
Portuguese situation. The evaluation of the respective impacts from a spatial perspective
raises questions such as: 1) What are the trade-offs of rural activity in different sectors
and regions? 2) How do such trade-offs cope with urban proximity?, and 3) Which
activities or strategies are best able to balance the needs of rural and urban communities.
Methodologically, our work identifies the land use change for the period 1990 – 2000
by comparing the databases CORINE Land Cover 90 and CORINE Land Cover 2000.
Further, in order to detect those sectors that, at national or regional level, have taken
more advantage of the CAP support, we present a new model, which also takes into
account as a major assumption the proximity of rural areas to the nearest towns.
The scope of this paper is twofold: addressing a specific problem concerning the
effectiveness of the CAP, it develops an extensive empirical and methodological
framework able to serve as a model-policy lesson for the rural/agricultural European
future
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