40,566 research outputs found
Managing data through the lens of an ontology
Ontology-based data management aims at managing data through the lens of an ontology, that is, a conceptual representation of the domain of interest in the underlying information system. This new paradigm provides several interesting features, many of which have already been proved effective in managing complex information systems. This article introduces the notion of ontology-based data management, illustrating the main ideas underlying the paradigm, and pointing out the importance of knowledge representation and automated reasoning for addressing the technical challenges it introduces
Automated Mapping of UML Activity Diagrams to Formal Specifications for Supporting Containment Checking
Business analysts and domain experts are often sketching the behaviors of a
software system using high-level models that are technology- and
platform-independent. The developers will refine and enrich these high-level
models with technical details. As a consequence, the refined models can deviate
from the original models over time, especially when the two kinds of models
evolve independently. In this context, we focus on behavior models; that is, we
aim to ensure that the refined, low-level behavior models conform to the
corresponding high-level behavior models. Based on existing formal verification
techniques, we propose containment checking as a means to assess whether the
system's behaviors described by the low-level models satisfy what has been
specified in the high-level counterparts. One of the major obstacles is how to
lessen the burden of creating formal specifications of the behavior models as
well as consistency constraints, which is a tedious and error-prone task when
done manually. Our approach presented in this paper aims at alleviating the
aforementioned challenges by considering the behavior models as verification
inputs and devising automated mappings of behavior models onto formal
properties and descriptions that can be directly used by model checkers. We
discuss various challenges in our approach and show the applicability of our
approach in illustrative scenarios.Comment: In Proceedings FESCA 2014, arXiv:1404.043
Using Event Calculus to Formalise Policy Specification and Analysis
As the interest in using policy-based approaches for systems management grows, it is becoming increasingly important to develop methods for performing analysis and refinement of policy specifications. Although this is an area that researchers have devoted some attention to, none of the proposed solutions address the issues of analysing specifications that combine authorisation and management policies; analysing policy specifications that contain constraints on the applicability of the policies; and performing a priori analysis of the specification that will both detect the presence of inconsistencies and explain the situations in which the conflict will occur. We present a method for transforming both policy and system behaviour specifications into a formal notation that is based on event calculus. Additionally it describes how this formalism can be used in conjunction with abductive reasoning techniques to perform a priori analysis of policy specifications for the various conflict types identified in the literature. Finally, it presents some initial thoughts on how this notation and analysis technique could be used to perform policy refinement
Coherent Integration of Databases by Abductive Logic Programming
We introduce an abductive method for a coherent integration of independent
data-sources. The idea is to compute a list of data-facts that should be
inserted to the amalgamated database or retracted from it in order to restore
its consistency. This method is implemented by an abductive solver, called
Asystem, that applies SLDNFA-resolution on a meta-theory that relates
different, possibly contradicting, input databases. We also give a pure
model-theoretic analysis of the possible ways to `recover' consistent data from
an inconsistent database in terms of those models of the database that exhibit
as minimal inconsistent information as reasonably possible. This allows us to
characterize the `recovered databases' in terms of the `preferred' (i.e., most
consistent) models of the theory. The outcome is an abductive-based application
that is sound and complete with respect to a corresponding model-based,
preferential semantics, and -- to the best of our knowledge -- is more
expressive (thus more general) than any other implementation of coherent
integration of databases
- …