Michel Billaud

A Distance Measurement Platform Dedicated to Electrical Engineering

This paper presents the remote laboratory eLab, dedicated to electrical engineering education. eLab is a flexible measurement platform that permits to run more than 130 experiments in the fields of electronics and microelectronics. The instructor can choose or create different types of pedagogical scenarios, covering teaching requirements from undergraduate to graduate levels. Furthermore, eLab implementation and use do not require any commercial software. Its reliability has been proven during many practical classes in France and other countries. eLab is now a key component of the Bordeaux University e-Learning material in electrical engineering. In the field of analog integrated circuits design, eLab offers a unique measurement solution, which can be combined to traditional circuit simulation sessions.

Graph rewriting systems with priorities

In this paper, we develop a new theory of attribute graph rewriting systems with priorities. This theory provides a very general tool for describing algorithms from classical graph theory, and for algorithms implemented on networks of communicating processors and distributed systems. Moreover, this theory gives an algebraic model which allows us to mathematically prove properties of distributed algorithms.

Real measures, virtual instruments

This paper presents the realisation of a remote lab on a European scale. The involved countries are France, Germany, and Spain. The architecture of the lab is described and the functionality has been tested. It concerns the instrumentation in the field of microelectronics. It has been applied to the characterisation of MOS transistors.

Axiomatizations of Backtracking

Goal schemes are terms built from a set of variables (representing goals) and the control structures {false, true, or, and} to which we give a sequential a la Prolog interpretation. We study equivalence relations induced by some interesting classes of elementary goals. We prove that, when goals are allowed to produce side-effects, or when they are restricted to have finite behaviours, there are finite complete axiomatizations that can be used to decide the equivalence of goal schemes. We conjecture that there is no such finite axiomatization in the case of general pure requests.

Fatal errors in conditional expressions

Abs t rac t . We propose a semantic model based on multivalued logic for the study of conditional expressions in programming languages. This model allows one to distinguish between different types of observable errors, whereas the coarser 3-valued model considers only one type of undefined result. We investigate the equational properties of this multivalued model. We present a finite equational basis for if-then-else, for the short-circuit operators +,.,-1, and also for the fully-evaluated operators (~, G. Finally, we present formulas for the number of distinct n-ary functions that can be expressed as combinations of short-circuit or fully-evaluated operators.

HeliosLab: A remote photovoltaic laboratory

This paper presents a project dedicated to the development of an open access remote PV laboratory for educational purposes. The remote PV laboratory will be installed outdoors at the facilities of the TEI of Athens - Greece, which is in a geographical region characterized by a large number of annual sunshine hours, allowing the users to perform real-world tests and experiments with photovoltaic panels over the internet, in real time. At the same time, the student can have a live view of the systems through a web camera, offering him/her a sense of personal presence in the place where the experiment takes place. The system will be accessible by everyone on the planet with an internet access and will be offered in at least five different languages. It also will be accompanied by appropriate educational material, for several target groups, such as students, postgraduates, professionals and educators, allowing it to be used by a broad variety of users directly. Moreover, the remote laboratory will help students with disabilities, to increase their participation in a laboratory environment.

Remote lab experiments for take away

This paper presents a new approach for the use of an already existing remote lab in the field on electrical engineer education. About 70 experiments representing a wide domain of electronic functions are easily accessible and can be incorporated in an existing teaching environment by an easy copy/paste action. The corresponding data base structure is explained and a typical result is given highlighting the procedure to follow.

ANIGRAF: an interactive system for the animation of graph rewriting systems with priorities

A PGRS is a finite set of rewriting rules, which do not modify the underlying graph, but only the labels attached to vertices or edges. There is a priority relation between rules, so when two occurrences of rules are overlapping in a graph, the rule with minor priority (if the rules are comparable) can not be applied to the graph. When the occurrences are not overlapping, both rules can be selected ; so checking whether a rule can be applied to a part of the graph does not require global informations.