Mickaël Baron

Bringing robustness to end-user programming

In some cases, end-user programming allows the design of stand-alone applications. But none of the existing approaches is concerned by safety aspects of programming. Heavy techniques exist to develop safe applications, particularly in non-interactive domains. They involve software engineering techniques, and sometimes, formal methods. All these techniques are very far from end-users. Our idea is to let this part to experts, and to connect end-user programming onto this safe conventional development. Starting from an existing functional core, we built an interactive end-user programming environment called GenBuild, which allows designing interactive stand-alone applications. GenBuild allows the verification of some properties that are a first step towards the development of safe end-user programming.

Do Rule-Based Approaches Still Make Sense in Logical Data Warehouse Design?

As any product design, data warehouse applications follow a well-known life-cycle. Historically, it included only the physical phase, and had been gradually extended to include the conceptual and the logical phases. The management of phases either internally or intranally is dominated by rule-based approaches. More recently, a cost-based approach has been proposed to substitute rule-based approaches in the physical design phase in order to optimize queries. Unlike the traditional rule-based approach, it explores a huge search space of solutions (e.g., query execution plans), and then based on a cost-model, it selects the most suitable one(s). On the other hand, the logical design phase is still managed by rule-based approaches applied on the conceptual schema. In this paper, we propose to propagate the cost-based vision on the logical phase. As a consequence, the selection of a logical design of a given data warehouse schema becomes an optimization problem with a huge space search generated thanks to correlations (e.g. hierarchies) between data warehouse concepts. By the means of a cost model estimating the overall query processing cost, the best logical schema is selected. Finally, a case study using the Star Schema Benchmark is presented to show the effectiveness of our proposal.

OntoDBench: Interactively Benchmarking Ontology Storage in a Database

Nowadays, all ingredients are available for developing domain ontologies. This is due to the presence of various types of methodologies for creating domain ontologies [3]. The adoption of ontologies by real life applications generates mountains of ontological data that need techniques and tools to facilitate their storage, management and querying.

SUIDT: safe user interface design tool

SUIDT (Safe User Interface Design Tool) is a model-based system that allows building interactive systems with respect to the formal semantics of functional cores. It implements a complete cooperation between task models (abstract and concrete) with both the domain model and the presentation model, while ensuring the properties of the models. Last, it maintains all during the design cycle the links between every part of the system, even the functions of the functional core (the actual code).

Comparaison théorique et empirique de systèmes de bases de données sémantiques

Ontologies are more and more used in information systems. When the size of data described by ontologies can not be manage in main memory, information system designers have to use specialized databases called semantic databases. As these databases use different architectures, storage layouts and ontology languages, this task is complex. In this paper, we propose a comparison and evaluation of these systems in order to help information system designers identify a relevant semantic database. We first present a state of the art on ontologies, their languages and storage layouts and architectures of associated databases. Then we propose a model for semantic databases that capture their diversity. Finally we provide a cost model and performance evaluation of six industrial and academic semantic databases. MOTS-CLÉS : Ontologie, Base de données, Modèle de coût, Evaluation de performances

Développements formels d'interfaces multimodales fondés sur la preuve et le raffinement. Scénarios de développement

The software architecture models of interactive systems are based on the separation of the functional core from the interface itself. The development of this two modules implies the use of several different software engineering techniques and approaches. Due to the resulting heterogeneity, the validation of the system may become a hard task.ln the context of the RNRT Verbatim project, the study of different development scenarios for multimodal human interfaces has been conducted within the formal event B method. Refinement of specifications is put into practice in order tu structure developments and proofs for establishing the relevant properties of the system. The main interest of this paper is the link between both functional core and interface modules. Four different development scenarios are studied and compared.

SUIDT: a user interface builder for secure user interfaces

We present in this paper a new computer-aided design for user interfaces tool that leans on several well-defined formalisms. This development tool for end-users is called SUIDT (Safe User Interface Design Tool). It uses visual programming techniques to build every application model and allows building the final application with respect to all models.