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Fault-tolerant systems are expected to operate in a variety of devices ranging from standard PCs to embedded devices. In addition, the emergence of new software technologies has required these applications to meet the needs of heterogeneous software platforms. However, the existing approaches to build fault-tolerant systems are often targeted at a particular platform and software technology. The objective of this paper is to discuss the use of FlexFT-a generic component-based framework for the construction of adaptive fault-tolerant systems that can integrate and reuse technologies and deploy them across heterogeneous devices. Furthermore, FlexFT provides a standardized and interoperable interface for sensor observations by relying upon the "Sensor Web" paradigm established by the Open Geospatial Consortium (OGC). We have implemented a Java prototype of our framework and evaluated the potential benefits by carrying out case studies and performance measurements. By implementing and deploying these case studies in standard PCs as well as in sensor nodes, we show that FlexFT can cope with the problem of a wide degree of heterogeneity with minimal resource overheads.

This paper presents a model designed to provide formative assessment support in LMSs. Our model has pedagogical basis on Assessment Research studies and maps concepts and recommendations from this area onto Distance Education domain. A multi-agent architecture is presented as the basis of a technological solution defined for the proposed model.In addition, considerations about an initial validation of the model are presented.

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The wildfires caused by human occupation is one of the factors that most contributes to deforestation of conservation areas, resulting in a number of issues for ecological systems. Premature fire detections lead to the elimination or reduction of the damage that will be caused by a fire incident. Wireless sensor networks have been shown to be a good alternative for environmental monitoring applications, as they can collect and send information in real time, such as humidity, wind, and temperature of various parts of the forest. Due to problems such as power limitation, communication failure, and loss of nodes, the network topology is constantly changing, requiring mechanisms to achieve self-organization and fault tolerance. This article proposes the development of a model and application in self-organizing and fault-tolerant wireless sensor networks for fire detection in conservation areas. To achieve self-organization and fault tolerance, we rely on encouraged local interactions between neighboring nodes that monitor the same region and the coordination of tasks, through a supervisor node, equipped with a framework for developing component-based fault-tolerant applications. For the analysis and validation of both model and application, it was simulated 60 events in the network of sensors in a real scenario using the simulator Sinalgo. The results were classified as True (partial or absolute) or False (partial or absolute). In all, 45% of consensus identified a possible fault in the application and in only 35% there was absolute consensus.