8 resultados para OHMIC CONTACTS
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In this paper, we seek to examine the effect of comparisons and social capital on subjective well-being. Furthermore, we test if, through social influence and exposure, social capital is either an enhancer or appeaser of the comparison effect. Using the Latinobarómetro Survey (2007) we find that in contrast to most previous studies, the comparison effect on well-being is positive; that is, the better others perform, the happier the individual is. We also find that social capital is among the strongest correlates of individuals’ subjective well-being in Latin American countries. Furthermore, our findings suggest that social contacts may enhance the comparison effect on individual’s happiness, which is more intense for those who perform worse in their reference group.
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How can networking affect the turnout in an election? We present a simple model to explain turnout as a result of a dynamic process of formation of the intention to vote within Erdös-Renyi random networks. Citizens have fixed preferences for one of two parties and are embedded in a given social network. They decide whether or not to vote on the basis of the attitude of their immediate contacts. They may simply follow the behavior of the majority (followers) or make an adaptive local calculus of voting (Downsian behavior). So they either have the intention of voting when the majority of their neighbors are willing to vote too, or they vote when they perceive in their social neighborhood that elections are "close". We study the long run average turnout, interpreted as the actual turnout observed in an election. Depending on the combination of values of the two key parameters, the average connectivity and the probability of behaving as a follower or in a Downsian fashion, the system exhibits monostability (zero turnout), bistability (zero turnout and either moderate or high turnout) or tristability (zero, moderate and high turnout). This means, in particular, that for a wide range of values of both parameters, we obtain realistic turnout rates, i.e. between 50% and 90%.
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This paper presents a vaccination strategy for fighting against the propagation of epidemic diseases. The disease propagation is described by an SEIR (susceptible plus infected plus infectious plus removed populations) epidemic model. The model takes into account the total population amounts as a refrain for the illness transmission since its increase makes the contacts among susceptible and infected more difficult. The vaccination strategy is based on a continuous-time nonlinear control law synthesised via an exact feedback input-output linearization approach. An observer is incorporated into the control scheme to provide online estimates for the susceptible and infected populations in the case when their values are not available from online measurement but they are necessary to implement the control law. The vaccination control is generated based on the information provided by the observer. The control objective is to asymptotically eradicate the infection from the population so that the removed-by-immunity population asymptotically tracks the whole one without precise knowledge of the partial populations. The model positivity, the eradication of the infection under feedback vaccination laws and the stability properties as well as the asymptotic convergence of the estimation errors to zero as time tends to infinity are investigated.
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[EN]Nowadays, global society is more aware of electrical energy’s risks than never before, and electrical safety has turned a priority when a new installation is designed. So, a great protection to an unwanted electric hazard is required, being specially careful with indirect contacts. If a circuit has an insulation failure and an indirect contact is produced, there is risk of an accidental electrocution, risk that must be avoided by making a good choice of the grounding methodology and properly coordinating the electrical protections in the installation. In order to minimize that risk, a study of low voltage industrial and residential installation’s grounding methodologies is introduced, analyzing the tree grounding methodologies internationally accepted (TT, TN, IT). In addition, two real examples are solved (using a computer-aided engineering software), confirming the results of the theoretical study.
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In this work a chain of 4000 silver nanoparticles embedded in a glass medium is considered, and its leftmost particle is excited by an electric field pulse of Gaussian shape. Considering Drude’s model, losses of the system are taken into account by γ factor, which stands for the Ohmic losses, and different quantities, such as frequencies of excited modes and group velocities are calculated. Besides, these results are compared to those obtained from the dispersion relation of an infinite chain. The increase of losses affects the lifetime and propagation length of the plasmon; besides, although the response dispersion relation for an infinite chain seems to remain invariable, this is not the case for a finite chain. The mismatches are bigger for higher losses. Furthermore, plasmon propagation velocities are analysed, and an explanation for the mismatch of longitudinal modes close to the intersection point with the dispersion of light is suggested. Finally, some concepts to treat this problem from the energy transport point of view are introduced.