Biblio

The growing maturity of orchestration languages is contributing to the elaboration of cloud composite services, whose resources may be deployed over different distributed infrastructures. These composite services are subject to changes over time, that are typically required to support cloud properties, such as scalability and rapid elasticity. In particular, the migration of their elementary resources may be triggered by performance constraints. However, changes induced by this migration may introduce vulnerabilities that may compromise the resources, or even the whole cloud service. In that context, we propose an automated SMT1-based security framework for supporting the migration of resources in cloud composite services, and preventing the occurrence of new configuration vulnerabilities. We formalize the underlying security automation based on SMT solving, in order to assess the migrated resources and select adequate counter-measures, considering both endogenous and exogenous security mechanisms. We then evaluate its benefits and limits through large series of experiments based on a proof-of-concept prototype implemented over the CVC4 commonly-used open-source solver. These experiments show a minimal overhead with regular operating systems deployed in cloud environments.

The article analyzes the concept of "Resilience" in relation to the development of computing. The strategy for reacting to perturbations in this process can be based either on "harsh Resistance" or "smarter Elasticity." Our "Models" are descriptive in defining the path of evolutionary development as structuring under the perturbations of the natural order and enable the analysis of the relationship among models, structures and factors of evolution. Among those, two features are critical: parallelism and "fuzziness", which to a large extent determine the rate of change of computing development, especially in critical applications. Both reversible and irreversible development processes related to elastic and resistant methods of problem solving are discussed. The sources of perturbations are located in vicinity of the resource boundaries, related to growing problem size with progress combined with the lack of computational "checkability" of resources i.e. data with inadequate models, methodologies and means. As a case study, the problem of hidden faults caused by the growth, the deficit of resources, and the checkability of digital circuits in critical applications is analyzed.

The coupled thermohydroelastic processes of acoustic wave and heat propagation in weak viscous fluid and elastic bodies form the basis of dissipative acoustics. The problems of dissipative acoustics have many applications in engineering practice, in particular in the development of appropriate medical equipment. This paper presents mathematical models for time and frequency domain problems in terms of unknown displacements and temperatures in both the fluid and the elastic body. Formulated corresponding variational problems and constructed numerical schemes for their solution based on the Galerkin approximations. The method of proving the well-posedness of the considered variational problems is proposed.