Rafik Bouaziz

Database design and querying within the fuzzy semantic model

Fuzzy semantic model (FSM) is a data model that uses basic concepts of semantic modeling and supports handling fuzziness, uncertainty and imprecision of real-world at the attribute, entity and class levels. The paper presents the principles and constructs of the FSM. It proposes ways to define the membership functions within all the constructs of the FSM. In addition, it provides a proposal for specifying FSM schema and introduce a query language adapted to FSM-based databases.

How to Model a Real-Time Database?

This paper presents a framework for real-time database design that is able to support real-time database requirements such as time-constrained data and time-constrained transactions. It is based upon a real-time object-oriented data model in which each object encapsulates time-constrained data, time-constrained methods and concurrency control mechanisms. Our framework is composed of an UML profile for real-time database, a translator to object-relational model, and an UML CASE Tool.

Dealing with Similarity Relations in Fuzzy Ontologies

Crisp ontologies become less suitable in all domains in which the concepts to be represented have imprecise definitions. Fuzzy ontologies are developed to overcome this problem. Determining similarity relations among fuzzy ontology components is essential for many reuse subprocesses, for query rewriting as well as for fuzzy ontology modeling. Denning similarity relations within fuzzy context may be realized basing on the linguistic similarity among ontology components or may be deduced from their intensional definitions. The later approach needs to be dealt with differently in crisp and fuzzy ontologies. In the first case, two ontology components are related by a given similarity relation or not. In the second one, two ontology components have a degree to be related by a given similarity relation. This is the scope of this paper.

Structural Model of Real-Time Databases: An Illustration

A real-time database is a database in which both the data and the operations upon the data may have timing constraints. The design of this kind of database requires the introduction of new concepts to modelize both data structures and the dynamic behavior of the database. In this paper, we propose an UML2.0 profile, entitled UML-RTDB, allowing the design of structural model for a real-time database. One of the main advantages of UML-RTDB is its capacity to take into account real-time database properties through specialized concepts in rigourous, easy and expressive manner.

Schema versioning in τXSchema-based multitemporal XML repositories

τXSchema [7] is a framework (a language and a suite of tools) for the creation and validation of time-varying XML documents. A τXSchema schema is composed of a conventional XML Schema document annotated with physical and logical annotations. All components of a τXSchema schema (i.e., conventional schema, logical annotations, and physical annotations) can change over time to reflect changes in user requirements or in reference world of the database. Since many applications need to keep track of both data and schema evolution, schema versioning has been long advocated to be the best solution to do this. In this paper, we deal with schema versioning in the τXSchema framework. More precisely, we propose a set of schema change primitives for the maintenance of logical and physical annotations and define their operational semantics.

Fuzzy ontologies building method: Fuzzy OntoMethodology

Building ontologies is very important for diverse domains and especially for semantic Web. We find in the literature many methods and tools for this building. However, the fuzzy aspect is not enough studied in these methods and tools, whereas information systems can include uncertainties and imperfections. The goal of the definition of fuzzy ontologies is to integrate these characteristics. So, we must be able to modulate uncertainties, on the one hand, and to product representations accessible and understandable by machines, on the other hand. If we find actually many building methods and editors for classic ontologies (i.e., crisp or exact), we do not find such methods for fuzzy ontologies. Then, this paper defines our work for fuzzy ontologies building. It presents our fuzzy ontologies building method “Fuzzy OntoMethodology”.

Modeling Real-Time Applications with Reusable Design Patterns

Real-Time (RT) applications, which manipulate important volumes of data, need to be managed with RT databases that deal with time-constrained data and time-constrained transactions. In spite of their numerous advantages, RT databases development remains a complex task, since developers must study many design issues related to the RT domain. In this paper, we tackle this problem by proposing RT design patterns that allow the modeling of structural and behavioral aspects of RT databases. We show how RT design patterns can provide design assistance through architecture reuse of reoccurring design problems. In addition, we present an UML profile that represents patterns and facilitates further their reuse. This profile proposes, on one hand, UML extensions allowing to model the variability of patterns in the RT context and, on another hand, extensions inspired from the MARTE (Modeling and Analysis of Real-Time Embedded systems) profile.

Versions to Address Business Process Flexibility Issue

This paper contributes to address an important issue in business process management: the Business Process (BP) flexibility issue. First, it defends that versions are an interesting solution to deal with both a priori (when designing BPs) and a posteriori (when executing BPs) flexibility. It also explains why previous contributions about versions of BPs are incomplete, and need to be revisited. Then, the paper presents a meta-model for BP versions, which combines five perspectives -the functional, process, informational, organizational and operation perspectives- for BP modelling, and which allows a comprehensive description of versionalized BPs.

Flexibility of collaborative processes using versions and adaptation patterns

Process aware Information Systems (PaIS) have an ever-increasing importance in Enterprise Information Systems for supporting both their intra and inter-organizational processes. However PaIS still have important issues to address, including flexibility of inter-organizational (i.e., collaborative) processes before their definitive acceptance and their use in companies. This paper addresses this issue advocating (i) the modelling of collaborative processes as BPMN collaboration, (ii) the use of the version notion to deal with collaborative process flexibility and to make process instance migration easier, and (iii) the introduction of 6 new adaptation patterns which are high-level operations for collaborative process schema update.

Querying fuzzy RDFS semantic annotations

The Semantic Web is an infrastructure that enables the interchange, the integration and the reasoning about information on the Web. In the Semantic Web, the resources are described using particular metadata called “Semantic annotations”. A semantic annotation is a particular case of annotation which refers to ontology. The Web content is, for the most part, subject to uncertainty or imperfection. If many extensions of ontology languages have been proposed to deal with fuzzyness on the Semantic Web, the problem of fuzzy ontology querying is not well treated. We propose in this paper a fuzzy extension of the RDFS model. We propose a new query language named FSAQL to query fuzzy RDFS semantic annotations. We define the syntax and the semantics of this language and the way to evaluate it.