The natural history of bugs: using formal methods to analyse software related failures in space missions

Space missions force engineers to make complex trade-offs between many different constraints including cost, mass, power, functionality and reliability. These constraints create a continual need to innovate. Many advances rely upon software, for instance to control and monitor the next generation ‘electron cyclotron resonance’ ion-drives for deep space missions.Programmers face numerous challenges. It is extremely difficult to conduct valid ground-based tests for the code used in space missions. Abstract models and simulations of satellites can be misleading. These issues are compounded by the use of ‘band-aid’ software to fix design mistakes and compromises in other aspects of space systems engineering. Programmers must often re-code missions in flight. This introduces considerable risks. It should, therefore, not be a surprise that so many space missions fail to achieve their objectives. The costs of failure are considerable. Small launch vehicles, such as the U.S. Pegasus system, cost around $18 million. Payloads range from$4 million up to $1 billion for security related satellites. These costs do not include consequent business losses. In 2005, Intelsat wrote off$73 million from the failure of a single uninsured satellite. It is clearly important that we learn as much as possible from those failures that do occur. The following pages examine the roles that formal methods might play in the analysis of software failures in space missions

Children's spontaneous correction of false beliefs in a conversation partner.

Preschool children were tested for their ability to vary the verbal information they offered regarding an object's location depending on whether the person searching for that object was likely to infer or misinfer its location. Older children (mean age: 5 years 3 months) offered information in a selective fashion: If the location of the hidden object could be readily inferred by their conversation partner, they indicated its location only when explicitly asked but if its location was likely to be misinferred, they often indicated that location prior to being explicitly asked. The response pattern of younger children (mean age: 3 years 6 months) was less conclusive. A relatively large number of younger children took matters "into their own hands" and immediately grasped for the concealed object, irrespective of whether its location could be readily inferred. However, the reactions of the remaining 3-year-olds suggest that even at this age children may be sensitive to the likely beliefs of their conversation partner. © 1999 The International Society for the Study of Behavioural Development

Using the Unified Foundational Ontology (UFO) as a Foundation for General Conceptual Modeling Languages

Abstract. In recent years, there has been a growing interest in approaches that employ ontological models as theoretical tools for analyzing and improving conceptual modeling languages. In this paper we present a philosophically and cognitively well-founded formal ontology which has been developed with the special purpose of serving as a foundation for general conceptual modeling lan-guages. Furthermore, we demonstrate how this foundational ontology named the Unified Foundational Ontology (UFO) has been used to evaluate and redes-ign the metamodel of the Unified Modeling Language (UML) for the purpose of conceptual modeling.

The Structure of Episodic Memory: Ganeri's ‘Mental Time Travel and Attention’

We offer a framework for assessing what the structure of episodic memory might be, if one accepts the Buddhist denial of persisting selves. This paper is a response to Jonardon Ganeri's paper "Mental time travel and attention", which explores Buddhaghosa's ideas about memory. (It will eventually be published with a reply by Ganeri)

Being (im)polite: A forensic linguistic approach to interpreting a hate speech case

In a hate speech case a court might have to determine whether a person’s words were hurtful or harmful. Would it be possible to determine whether words are hurtful or harmful by using linguistics? This article offers a linguistic perspective on a court’s interpretation of the Equality Act in a hate speech case and focuses on speech acts and politeness. If the speech acts of a verbal exchange are studied and the levels of politeness are gauged, a court would be able to affi rm the hurtfulness or harmfulness of the speaker’s words. The article begins with a brief discussion on the potential role of the linguist in a courtroom; this is followed by a summary of the facts of the case. Then the court case is analysed and discussed in terms of speech acts and politeness. By employing principles in pragmatics the author reaches the same conclusion as the court.Afrikaans and Theory of Literatur