Capabilities are a more scalable and adaptive access control approach compared with the conventional approaches such as ACLs, due to their being held and managed by users or agents in systems, but not the middleware. This feature makes capabilities more suitable in distributed environments that have dynamic populations. Treaties have been proposed to enhance the capability approach by introduci...

This paper uses a methodology based in fuzzy sets theory in order to describe the interaction between the prey, Aphis glycines (Hemiptera: Aphididae) the soybean aphid, and its predator, Orius insidiosus (Hemiptera: Anthocoridae) and to propose a chemical control for soybean aphid. Economic thresholds were already developed for this pest. The model includes biotic (predator) and abiotic (temper...

We obtain the optimal harvesting plan to maximize the expected discounted number of individuals harvested over an infinite future horizon, under the most common (»erhulst-Pearl) logistic model for a stochastically fluctuating population. We also solve the problem for the standard variants of the model where there are constraints on the admissible harvesting rates. We use stochastic calculus to ...

The wireless revolution has enabled a new generation of applications for nomadic users. In this work we propose a new paradigm for the creation of games based on virtual worlds that are hosted on mobile devices. Each time mobile devices “get in touch”, their virtual worlds have the opportunity to interact. This form of interaction is based on the remote control of a subset of the agents that po...

We consider the harvest of a certain proportion of a population that is modeled by an integro-difference equation. This model is discrete in time and continuous in the space variable. The dispersal of the population is modeled by an integral of the population density against a kernel function. The control is the harvest, and the goal is to maximize the profit. The optimal control is characteriz...