2,244 research outputs found
Contribution of simulation and gaming to natural resource management issues: An introduction
Nowadays, computer-mediated simulations and games are widely used in the field of natural resource management (NRM). They have proved to be useful for various purposes such as supporting decisionmaking processes and training. First, the specificities of the NRM research field are highlighted. Then, based on the analysis of the articles presented in this special issue of Simulation & Gaming, some key features related to the implementation of gaming in such a context are introduced. Finally, after reviewing the benefits of using simulation games in NRM, the authors stress the ethical issue of changing social relationships among stakeholders by playing a game with some of themGESTION DE L'ENVIRONNEMENT;RESSOURCE NATURELLE;SIMULATION;SOCIOLOGIE;JEU DE ROLE;BENEFITS;CONTEXT;COLLECTIVE POLICY DESIGN;DECISION MAKING;ETHICAL ISSUES;IMPLEMENTATION;NATURAL RESOURCE MANAGEMENT (NRM);SIMULATION GAMES;SOCIAL EMPOWERMENT;SOCIAL RELATIONSHIPS;SOCIOECOLOGICAL SYSTEMS;STAKEHOLDERS
Arbitrage and Equilibrium in Economies with Externalities.
We introduce consumption externalities into a general equilibrium model with arbitrary consumption sets. To treat the problem of existence of equilibrium, a condition of no unbounded arbitrage, extending the condition of Page (1987) and Page and Wooders (1993, 1996) is defined. It is proven that this condition is sufficient for the existence of an equilibrium and both necessary and sufficient for compactness of the set of rational allocations.CONSUMPTION ; EXTERNALITIES ; ARBITRAGE
The survival probability of a critical multi-type branching process in i.i.d. random environment
Conditioned on the generating functions of offspring distribution, we study the asymp-totic behaviour of the probability of non-extinction of a critical multi-type Galton-Watson process in i.i.d. random environments by using limits theorems for products of positive random matrices. Under some certain assumptions, the survival probability is proportional to 1/ √ n
Diagnostics for specific PAHs in the far-IR: searching neutral naphthalene and anthracene in the Red Rectangle
Context. In the framework of the interstellar polycyclic aromatic
hydrocarbons (PAHs) hypothesis, far-IR skeletal bands are expected to be a
fingerprint of single species in this class. Aims. We address the question of
detectability of low energy PAH vibrational bands, with respect to spectral
contrast and intensity ratio with ``classical'' Aromatic Infrared Bands (AIBs).
Methods. We extend our extablished Monte-Carlo model of the photophysics of
specific PAHs in astronomical environments, to include rotational and
anharmonic band structure. The required molecular parameters were calculated in
the framework of the Density Functional Theory. Results. We calculate the
detailed spectral profiles of three low-energy vibrational bands of neutral
naphthalene, and four low-energy vibrational bands of neutral anthracene. They
are used to establish detectability constraints based on intensity ratios with
``classical'' AIBs. A general procedure is suggested to select promising
diagnostics, and tested on available Infrared Space Observatory data for the
Red Rectangle nebula. Conclusions. The search for single, specific PAHs in the
far-IR is a challenging, but promising task, especially in view of the
forthcoming launch of the Herschel Space Observatory.Comment: 13 pages, 13 figures, accepted for publication in A&
Global fire activity patterns (1996-2006) and climatic influence: an analysis using World Fire Atlas
Vegetation fires have been acknowledged as an environmental
process of global scale, which affects the chemical
composition of the troposphere, and has profound ecological
and climatic impacts. However, considerable uncertainty
remains, especially concerning intra and inter-annual
variability of fire incidence. The main goals of our globalscale
study were to characterise spatial-temporal patterns of
fire activity, to identify broad geographical areas with similar
vegetation fire dynamics, and to analyse the relationship
between fire activity and the El Ni˜no-Southern Oscillation.
This study relies on 10 years (mid 1996–mid
2006) of screened European Space Agency World Fire Atlas
(WFA) data, obtained from Along Track Scanning Radiometer
(ATSR) and Advanced ATSR (AATSR) imagery.
Empirical Orthogonal Function analysis was used to reduce
the dimensionality of the dataset. Regions of homogeneous
fire dynamics were identified with cluster analysis, and interpreted
based on their eco-climatic characteristics. The
impact of 1997–1998 El Ni˜no is clearly dominant over the
study period, causing increased fire activity in a variety of
regions and ecosystems, with variable timing. Overall, this
study provides the first global decadal assessment of spatialtemporal
fire variability and confirms the usefulness of the
screened WFA for global fire ecoclimatology researc
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