Towards Generic Monitors for Object-Oriented Real-Time Maude Specifications

Non-Functional Properties (NFPs) are crucial in the design of software. Specification of systems is used in the very first phases of the software development process for the stakeholders to make decisions on which architecture or platform to use. These specifications may be an- alyzed using different formalisms and techniques, simulation being one of them. During a simulation, the relevant data involved in the anal- ysis of the NFPs of interest can be measured using monitors. In this work, we show how monitors can be parametrically specified so that the instrumentation of specifications to be monitored can be automatically performed. We prove that the original specification and the automati- cally obtained specification with monitors are bisimilar by construction. This means that the changes made on the original system by adding monitors do not affect its behavior. This approach allows us to have a library of possible monitors that can be safely added to analyze different properties, possibly on different objects of our systems, at will.Universidad de Málaga, Campus de Excelencia Internacional Andalucía Tech. Spanish MINECO/FEDER project TIN2014-52034-R, NSF Grant CNS 13-19109

Jamming in frictionless packings of spheres: determination of the critical volume fraction

The jamming transition in granular packings is characterized by a sudden change in the coordination number. In this work we investigate the evolution of coordination number as function of volume fraction for frictionless packings of spheres undergoing isotropic deformation. Using the results obtained from Discrete Element Method simulations, we confirm that the coordination number depends on volume fraction by a power law with exponent α≈0.5 above the critical volume fraction and up to rather high densities. We find that the system size and loading rate do not have an important effect on the evolution of the coordination number. Polydispersity of the packing seems to cause a shift in the critical volume fraction, i.e., more heterogeneous packings jam at higher volume fractions. Finally, we propose and evaluate alternative methods to determine the critical volume fraction based on the number of rattlers, the pressure and the ratio of kinetic and potential energies. The results are all consistent with the critical volume fractions obtained from the fits of the power law to the simulation data

Simple regular black hole with logarithmic entropy correction

A simple regular black hole solution satisfying the weak energy condition is obtained within Einstein--non--linear electrodynamics theory. We have computed the thermodynamic properties of this black hole by a careful analysis of the horizons and we have found that the usual Bekenstein--Hawking entropy gets corrected by a logarithmic term. Therefore, in this sense our model realizes some quantum gravity predictions which add this kind of correction to the black hole entropy. In particular, we have established some similitudes between our model and a quadratic generalized uncertainty principle. This similitude has been confirmed by the existence of a remnant, which prevents complete evaporation, in agreement with the quadratic generalized uncertainty principle case