Ontology-Based Data Access and Integration

An ontology-based data integration (OBDI) system is an information management system consisting of three components: an ontology, a set of data sources, and the mapping between the two. The ontology is a conceptual, formal description of the domain of interest to a given organization (or a community of users), expressed in terms of relevant concepts, attributes of concepts, relationships between concepts, and logical assertions characterizing the domain knowledge. The data sources are the repositories accessible by the organization where data concerning the domain are stored. In the general case, such repositories are numerous, heterogeneous, each one managed and maintained independently from the others. The mapping is a precise specification of the correspondence between the data contained in the data sources and the elements of the ontology. The main purpose of an OBDI system is to allow information consumers to query the data using the elements in the ontology as predicates. In the special case where the organization manages a single data source, the term ontology-based data access (ODBA) system is used

The foundational legacy of ASL

Abstract. We recall the kernel algebraic specification language ASL and outline its main features in the context of the state of research on algebraic specification at the time it was conceived in the early 1980s. We discuss the most significant new ideas in ASL and the influence they had on subsequent developments in the field and on our own work in particular.

Adopting Architectural Event Modules for Modular Coordination of Multiple Applications

Nowadays, large-scale software systems consist of multiple applications, which interact with each other to fulfill desired system-level requirements. It is usually required to coordinate the interactions of the constituent applications to ensure that the system-level requirements are fulfilled. In this paper, we outline a set of requirements that must be fulfilled to facilitate the modular composition of multiple applications. We introduce the concept of architectural event modules, which are abstractions to represent constituent applications and their coordination logic in a modular and uniform way. We explain the implementation of this concept in the EventReactor language, and define their formal semantics in processing events using the UPPAAL toolset. We illustrate the suitability of architectural event modules in achieving modularity and loose coupling in the composition of multiple applications by means of a case study in the domain of energy-efficient computing

Experiences In Migrating An Industrial Application To Aspects

Aspect-Oriented Software Development (AOSD) is a paradigm aiming to solve problems of object-oriented programming (OOP). With normal OOP it’s often unlikely to accomplish fine system modularity due to crosscutting concerns being scattered and tangled throughout the system. AOSD resolves this problem by its capability to crosscut the regular code and as a consequence transfer the crosscutting concerns to a single model called aspect. This thesis describes an experiment on industrial application wherein the effectiveness of aspect-oriented techniques is explained in migration the OOP application into aspects. The experiment goals at first to identify the crosscutting concerns in source code of the industrial application and transform these concerns to a functionally equivalent aspect-oriented version. In addition to presenting experiences gained through the experiment, the thesis aims to provide practical guidance of aspect solutions in a real application

Truly modular (co)datatypes for Isabelle/HOL

We extended Isabelle/HOL with a pair of definitional commands for datatypes and codatatypes. They support mutual and nested (co)recursion through well-behaved type constructors, including mixed recursion–corecursion, and are complemented by syntaxes for introducing primitive (co)recursive functions and by a general proof method for reasoning coinductively. As a case study, we ported Isabelle’s Coinductive library to use the new commands, eliminating the need for tedious ad hoc constructions