Expressing Measurement Uncertainty in OCL/UML Datatypes

Uncertainty is an inherent property of any measure or estimation performed in any physical setting, and therefore it needs to be considered when modeling systems that manage real data. Although several modeling languages permit the representation of measurement uncertainty for describing certain system attributes, these aspects are not normally incorporated into their type systems. Thus, operating with uncertain values and propagating uncertainty are normally cumbersome processes, di cult to achieve at the model level. This paper proposes an extension of OCL and UML datatypes to incorporate data uncertainty coming from physical measurements or user estimations into the models, along with the set of operations de ned for the values of these types.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

State-of-Science review: learning difficulties: SR-D4: Dyscalculia

Low numeracy skills in general and developmental dyscalculia (DD) in particular constitute a severe handicap. This review examines the causes and behavioural manifestations of numeracy deficits, their neuropsychological correlates and the limits to our understanding of these conditions. It then goes on to describe a validated test for diagnosing DD – a specific impairment in the capacity to learn arithmetic. The challenges in educating DD children and analysing their particular intervention needs are described. Reference is also made to the impact of dyscalculia on mental health (and ill-health) and individual wellbeing

Polymorphism - prose of Java programmers

In Java programming language as implemented in JDK 5.0 there appear rather advanced kinds of polymorphism, even if they are hidden under different names. The notion of polymorphism unifies many concepts present in typed programming languages, not necessary object-oriented. We briefly define some varieties of polymorphism and trace them in Java. Java shows that industrial programming languages are able to express more abstract patterns using rather involved theoretical means, hence the working programmer has to be better educated in order to understand them, recognize them in different programming languages under different names and superficial syntax, and make good use of them

What Are Polymorphically-Typed Ambients?

Abstract: The Ambient Calculus was developed by Cardelli and Gordon as a formal framework to study issues of mobility and migrant code. We consider an Ambient Calculus where ambients transport and exchange programs rather that just inert data. We propose different senses in which such a calculus can be said to be polymorphically typed, and design accordingly a polymorphic type system for it. Our type system assigns types to embedded programs and what we call behaviors to processes; a denotational semantics of behaviors is then proposed, here called trace semantics, underlying much of the remaining analysis. We state and prove a Subject Reduction property for our polymorphically typed calculus. Based on techniques borrowed from finite automata theory, type-checking of fully type-annotated processes is shown to be decidable; the time complexity of our decision procedure is exponential (this is a worst-case in theory, arguably not encountered in practice). Our polymorphically-typed calculus is a conservative extension of the typed Ambient Calculus originally proposed by Cardelli and Gordon

Polymorphic Type Inference in Scheme

This paper presents a type-inference system for Scheme that is designed to be used by students in an introductory programming course. The major goal of the work is to present a simple type inference system that can be used by beginning students, yet is powerful enough to express the ideas of types, polymorphism, abstract data types, and higher-order procedures. The system also performs some rudimentary syntax checking. The system uses subtyping, but only in a primitive fashion. It has a type datum which is a supertype of all types, and a type poof which is a subtype of all types. It uses and-types (intersection types) to control the use of datum and to generate accurate but simple types