L’analyse bioénergétique

L'auteur présente les principales composantes de l'analyse bionergétique.The author presents the main components of bioenergetic analysis

Investigating in Security Solutions - Can Qualified Electronic Signatures be Profitable for Mobile Operators?

Electronic signatures are an established method to ensure the integrity and accountability of electronic transactions. Realizing their potential, the European Parliament and the Council enacted the directive 1999/93/EC in 1999, providing legal requirements for a common introduction of electronic signatures in Europe. However, so far the signature market has failed miserably. Mobile electronic signatures are often seen as a potential and promising way to provide market acceptance for electronic signatures. This paper proposes an infrastructure for qualified mobile electronic signatures that does not require the mobile operator to act as a certificate service provider (CSP). The user can freely choose a CSP and add the signature functionality along with the required certificates later on demand. However, mobile operators will only invest in this infrastructure, if they expect a return on investment (ROI). Therefore, based on our proposed infrastructure and using distinct scenarios, we conducted an investment analysis for mobile operators forecasting the net present value and the internal rate of return of the investment. Our forecast shows that issuing signature capable smart cards can be quite profitable for a mobile operator

Enterprise Identity Management – Towards a Decision Support Framework Based on the Balanced Scorecard Approach

Enterprise Identity Management Systems (EIdMS) are an IT-based infrastructure that needs to be integrated into various business processes and related infrastructures. Assessment and preparation of decisions for the introduction need to take the costs, benefits, and the organizational settings into consideration. A variety of methods for the evaluation and decision support of new IT (e. g. EIdMS) are discussed in the literature – however, these are typically based on single dimensions (e. g. financial or technology aspects). This paper proposes a multidimensional decision support framework, based on the Balanced Scorecard concept. The presented approach introduces four perspectives and a related set of initial decision parameters to support decision making. The perspectives are (a) financial/monetary, (b) business processes, (c) supporting processes and (ICT) infrastructure and (d) information security, risks and compliance. Perspectives and adaptable sets of decision parameters also may serve as foundation for software-based decision support instruments

Acoustics of a porous medium saturated by a bubbly fluid undergoing phase change

International audienceThe objective of this work is the derivation of the wave equations for describing acoustics in a deformable porous medium saturated by a bubbly fluid, when capillary, thermal and phase change effects are accounted for. This is performed using an homogenisation technique: the macroscopic model is obtained by upscaling the bubble-scale and the pore-scale descriptions. For convenience a bubbly fluid near the bubble point, in the bulk of which a small perturbation can generate small bubbles is considered. Although the derived macroscopic wave equations are similar in their structure to Biot's equations that describe wave propagation in saturated porous media, important differences appear as a result of the presence of bubbles. In effect, gas-liquid phase change considerably decreases the apparent rigidity of the bubbly fluid, and consequently decreases the wave velocity in the porous medium. Moreover, this phenomenon is amplified for very small bubbles, for which the apparent rigidity of the bubbly fluid can be negative. The influence of the bubbly liquid apparent rigidity on the wave velocity and attenuation is highlighted on an illustrative example: it is shown that they strongly differ from wave velocities and attenuations in porous media saturated by a liquid or by a gas

Recreational Needs and Practices of Youth Living in Rural Areas in Quebec: Views and Concerns of Stakeholders and Parents

Public recreation in rural areas is often a key factor in fighting the devitalization of small municipalities. Additionally, recreational activities support youth in their identity and social development, for instance through generated social interactions. Based on a qualitative case study conducted in Quebec, this research seeks to identify the needs and sought-after forms of recreational activities for youth living in rural areas according to local stakeholders and parents, and, simultaneously, to estimate land management, governance, and social actions that will improve the recreational offer already in place. Results show that the interviewed stakeholders are aware of the merits of leisure for youth and acknowledge the need to take action to enhance recreational services and to make practice areas more accessible. In addition, they all believe that encouraging youth to get involved in their communities to make their living environments even more dynamic and attractive is essential

Bulletin agrométéorologique - Situation au 30 juin 2010

A la fin du mois de juin, les conditions météorologiques peuvent être qualifiées de globalement bonnes sur la plus grande partie du territoire belge. De bons rendements sont annoncés sans toutefois atteindre les rendements exceptionnels comme ceux du blé de l’an dernier. Les analyses spatiales dérivées de la télédétection confirment cette tendance favorable tout en indiquant une hétérogénéité importante dans certaines régions du pays qui peut être mise sur le compte de précipitations orageuses localisées. Les conditions climatiques des prochaines semaines seront déterminantes pour conserver tous les bons potentiels de rendement des cultures et éviter que la situation ne se dégrade pour les zones à plus faible potentiel

Bulletin agrométéorologique - Situation au 21 juin 2009

Depuis le dernier bulletin publié fin avril, les conditions météorologiques ont été fort proches des normales avec toutefois quelques épisodes orageux qui ont pu causer ça et là des dégâts aux cultures. La végétation semble avoir ralenti davantage sa croissance que ce qui s’observe d’habitude depuis dix ans, cela en particulier dans le Nord et le Nord-Ouest du pays, probablement en raison des conditions pluvieuses rencontrées dans ces zones. Cependant les prévisions de rendements à l’échelle nationale ne semblent pas être affectées. A l’exception du maïs, les rendements s’annoncent meilleurs que la moyenne des quatre dernières années

Bulletin agrométéorologique - Situation au 30 avril 2009

Alors que l’on pouvait craindre les conséquences de l’hiver froid que nous avons connu cette année, il apparaît, au niveau de nos indicateurs météorologiques et de nos indicateurs spatiaux dérivés de la télédétection, que les grandes cultures ont dans l’ensemble bien passé l’hiver et elles ont largement rattrapé le retard accumulé au cours des mois d’hiver et du tout début de printemps. Ceci se vérifie également sur le terrain où les stades phénologiques sont très proches de la situation normale. Aucune prévision de rendement n’est faite à ce stade

Resistance Evolution to Bt Crops: Predispersal Mating of European Corn Borers

Over the past decade, the high-dose refuge (HDR) strategy, aimed at delaying the evolution of pest resistance to Bacillus thuringiensis (Bt) toxins produced by transgenic crops, became mandatory in the United States and is being discussed for Europe. However, precopulatory dispersal and the mating rate between resident and immigrant individuals, two features influencing the efficiency of this strategy, have seldom been quantified in pests targeted by these toxins. We combined mark-recapture and biogeochemical marking over three breeding seasons to quantify these features directly in natural populations of Ostrinia nubilalis, a major lepidopteran corn pest. At the local scale, resident females mated regardless of males having dispersed beforehand or not, as assumed in the HDR strategy. Accordingly, 0–67% of resident females mating before dispersal did so with resident males, this percentage depending on the local proportion of resident males (0% to 67.2%). However, resident males rarely mated with immigrant females (which mostly arrived mated), the fraction of females mating before dispersal was variable and sometimes substantial (4.8% to 56.8%), and there was no evidence for male premating dispersal being higher. Hence, O. nubilalis probably mates at a more restricted spatial scale than previously assumed, a feature that may decrease the efficiency of the HDR strategy under certain circumstances, depending for example on crop rotation practices