Deriving Specifications of Dependable Systems: toward a Method

This paper proposes a method for deriving formal specifications of systems. To accomplish this task we pass through a non trivial number of steps, concepts and tools where the first one, the most important, is the concept of method itself, since we realized that computer science has a proliferation of languages but very few methods. We also propose the idea of Layered Fault Tolerant Specification (LFTS) to make the method extensible to dependable systems. The principle is layering the specification, for the sake of clarity, in (at least) two different levels, the first one for the normal behavior and the others (if more than one) for the abnormal. The abnormal behavior is described in terms of an Error Injector (EI) which represents a model of the erroneous interference coming from the environment. This structure has been inspired by the notion of idealized fault tolerant component but the combination of LFTS and EI using rely guarantee thinking to describe interference can be considered one of the main contributions of this work. The progress toward this method and the way to layer specifications has been made experimenting on the Transportation and the Automotive Case Studies of the DEPLOY project.Comment: Published in "12th European Workshop on Dependable Computing, EWDC 2009, Toulouse : France (2009)

On the Modeling of Correct Service Flows with BPEL4WS

Frameworks for composing Web Services offer a promising approach for realizing enterprise-wide and cross-organizational business applications. With BPEL4WS a powerful composition language exists. BPEL implementations allow orchestrating complex, stateful interactions among Web Services in a process-oriented way. One important task in this context is to ensure that respective flow specifications can be correctly processed, i.e., there will be no bad surprises (e.g., deadlocks, invocation of service operations with missing input data) at runtime. In this paper we subdivide BPEL schemes into different classes and discuss to which extent instances of these classes can be analyzed for the absence of control flow errors and inconsistencies. Altogether our work shall contribute to a more systematic evolution of the BPEL standard instead of overloading it with too many features

Understanding and profiling user requirements to support the conceptual design of an integrated land monitoring system

Acquiring and organizing knowledge and information elements can be essential not only to understand, but also to eliminate, reduce and control complexity and uncertainty. An integration of tools from different disciplines could systematically help in the construction of an agreed framework for problem formulation, above all when the situation is "new". An application was de-veloped in relation to an industrial project, in order to propose profiles of the potential users of an innovative system and of their requirements, and to for-mally develop models that can orient analysis, decision and action. Some ele-ments and results of this integrated application of "soft" and "hard" decision aid tools are here proposed as steps of an organizational learning cycle, which is a basic element of each innovation proces

THE ISSUE OF SEMANTIC MODELING OF THE LEARNING ORGANIZATIONAL MEMORY FOR E-LEARNING

The development of open and long-distance learning – within universities but also withingeographically distributed enterprises –has led to the development of researches focusing on modeling onsemantic bases the learning organizational memory of an e-learning type. This paper reviews the literaturein the field, focusing on defining a generic template of semantic modeling of the content of the learningorganizational memory of the e-learning type, by proposing a study case of semantic representation oflearning objects applied to the economic-financial analysis. The research is both theoretic and applied-deductive in character, starting from a general background regarding learning in general and reachingparticularity by providing an ontology specific to the economic-financial analysis.learning organizational memory, learning object, ontology, metadata, indexing, e-learning,modeling standards, economical and financial analysis.

From internet architecture research to standards

Many Internet architectural research initiatives have been undertaken over last twenty years. None of them actually reached their intended goal: the evolution of the Internet architecture is still driven by its protocols not by genuine architectural evolutions. As this approach becomes the main limiting factor of Internet growth and application deployment, this paper proposes an alternative research path starting from the root causes (the progressive depletion of the design principles of the Internet) and motivates the need for a common architectural foundation. For this purpose, it proposes a practical methodology to incubate architectural research results as part of the standardization process

TURTLE-P: a UML profile for the formal validation of critical and distributed systems

The timed UML and RT-LOTOS environment, or TURTLE for short, extends UML class and activity diagrams with composition and temporal operators. TURTLE is a real-time UML profile with a formal semantics expressed in RT-LOTOS. Further, it is supported by a formal validation toolkit. This paper introduces TURTLE-P, an extended profile no longer restricted to the abstract modeling of distributed systems. Indeed, TURTLE-P addresses the concrete descriptions of communication architectures, including quality of service parameters (delay, jitter, etc.). This new profile enables co-design of hardware and software components with extended UML component and deployment diagrams. Properties of these diagrams can be evaluated and/or validated thanks to the formal semantics given in RT-LOTOS. The application of TURTLE-P is illustrated with a telecommunication satellite system