During their second year of a junior high school, pupils wrote programs for autonomous mini robots using a Logo-like language supplemented by an integrated development environment specifically implemented for them. Then pupils and teachers together performed a static analysis of programs in order to specify the length of the paths each robot covers when programs are run. If a robot mounts sensors and the analyzed program uses them, the path covered during each run generally changes and has a different length. Pupils found that it can be specified with an expression containing variables. This analysis associating algebraic expressions to robot programs provided teachers for a support motivating elementary algebra, a typical subject addressed in junior high schools. Thus it is an example of how robotics can be used as means to introduce and concretely manipulate topics of traditional disciplines. It can be integrated in standard school curricula and become a constructionist learning tool for pupils involved in programming activities.

Small robots are very simple computers that can move autonomously. Their use in primary schools allows pupils to have concrete yet full programming experiences at the age in which Piaget situates the concrete operational stage of cognitive development. Indeed, for their first robotic activities, pupils think of paths where the robot moves forward, decides which direction to go when getting to a crossroad or repeats part of its previous trip. In planning a path for their robot, children walk it themselves thus finding out its successive tangible parts and related features. Our pupils use NQCBaby and NXCJunior programming languages for the formal specification of their robot's behaviour. These are textual languages, mother-tongue-based and Logo-like, in order to be oriented to children rather than to robots. Thus, when programming small robots, children are introduced to a deep computer competence because they deal with the basic blocks of algorithmics (sequence, selection and iteration) and learn how to specify them.

We study the evaluation of recursively defined virtual relations in logic databases. A contribution of our research, is to answer a query involving a recursive relation by executing either an iterative or a recursive procedure scheme depending on the variable instantiation of the query itself.

article Analysis of the context dependency of CODASYL find-statements with application to a database program conversion Share on Authors: G. Barbara Demo Dipartimento di Informatica Unversita di Tormo, 42 c M D'Azegho, 10125 Torino, ITALY Dipartimento di Informatica Unversita di Tormo, 42 c M D'Azegho, 10125 Torino, ITALYView Profile , Sukhamay Kundu Computer Science Department, Louisiana State University, Baton Rouge, LA Computer Science Department, Louisiana State University, Baton Rouge, LAView Profile Authors Info & Claims ACM SIGMOD RecordVolume 14Issue 4May 1985 pp 354–361https://doi.org/10.1145/971699.318936Online:01 May 1985Publication History 5citation203DownloadsMetricsTotal Citations5Total Downloads203Last 12 Months5Last 6 weeks2 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteGet Access

A consistent specification of quantitative processing characteristics is of crucial importance in order to obtain an efficient logical and physical database design. In this paper we propose a flow analysis of a Petri net representation of the interaction among operations within an organization function. The result of this analysis is the automa tic derivation of the operation activation frequencies. The project environment to which this analysis is relevant is also described.