Carlos Ribeiro Rodrigues

An ontology for managing network services quality

The evolution of IP networks to a service-oriented paradigm poses new challenges to service providers regarding the management and auditing of network services. The upward trend in ubiquity, heterogeneity and virtualization of network services and resources demands for a formal and systematic approach to network management tasks. In this context, the semantic characterization and modeling of services provided to users is a key component to sustain autonomic service management, service negotiation and configuration. The semantic and formal description of services and resources is also relevant to assist paradigms such as cloud computing, where a large diversity of resources have to be described and managed in a highly dynamic way. This paper defines an ontology for multiservice IP networks targeting multiple service management goals, namely: (i) to foster client and service provider interoperability; (ii) to manage network service contracts, promoting the dynamic negotiation between parties; (iii) to access and query SLA/SLSs data on a individual or aggregated basis to assist service provisioning in the network; and (iv) to sustain service monitoring and auditing. A ServiceModel API is provided to take full advantage of the proposed semantic model, allowing Service Management Platforms to access the ontological contents. This ontological development takes advantage of SWRL to discover new knowledge, enriching the possibilities of systems described using this support.

Residue of Phosphorus Sources Broadcast and Applied on Rows in Forages during Off-Season Crops

This study aimed to evaluate the residual effect of phosphorus sources and application techniques in the intercropping of forages during off-season crops. The experimental design was randomized blocks in a 4 × 2 + 1 factorial, being four sources of phosphorus [Bayovar Reactive Phosphate (BRP), Monoammonium Phosphate (MAP), Simple Superphosphate (SS) and Triple Superphosphate (TS)], two application techniques (broadcasting and on rows) and an additional without phosphorus. The experiment was conducted during the off-season crop. The residual effect of phosphorus fertilization increased the growth and the production of biomass of forage sorghum regarding broadcast SS and TS sources. The lowest P contents in the tissue of plants fertilized with SS and TS may be attributed to the diluting effect, as it achieved the highest production of biomass. The application of TS favored a greater dry matter production in Brachiaria brizantha cv. Piata. At the depth 0.00-0.05 m, there was a higher P content with the application of BRP. However, the production of biomass was low, a factor that may be related to an overestimation of P bound to Ca by the Mehlich-1 extractor. Under cultivation conditions, broadcast SS and TS had a higher residual effect.

A semantic model for enhancing network services management and auditing

The road toward ubiquity, heterogeneity and virtualization of network services and resources urges for a formal and systematic approach to network management tasks. In particular, the semantic characterization and modeling of services provided to users assume an essential role in fostering autonomic service management, service negotiation and auditing. This paper is centered on the definition of an ontology for multiservice IP networks which intends to address multiple service management goals, namely: (i) to foster client and service provider interoperability; (ii) to manage network service contracts, facilitating the dynamic negotiation between clients and ISPs; (iii) to access and query SLA/SLSs data on an individual or aggregated basis to assist service provisioning in the network; and (iv) to sustain service monitoring and auditing. In order to take full advantage of the proposed semantic model, a service model API is provided to allow service management platforms to access the ontological contents. This ontological development also takes advantage of SWRL to discover new knowledge, enriching the possibilities of systems described using this support.