Quantitative Verification: Formal Guarantees for Timeliness, Reliability and Performance

Computerised systems appear in almost all aspects of our daily lives, often in safety-critical scenarios such as embedded control systems in cars and aircraft or medical devices such as pacemakers and sensors. We are thus increasingly reliant on these systems working correctly, despite often operating in unpredictable or unreliable environments. Designers of such devices need ways to guarantee that they will operate in a reliable and efficient manner. Quantitative verification is a technique for analysing quantitative aspects of a system's design, such as timeliness, reliability or performance. It applies formal methods, based on a rigorous analysis of a mathematical model of the system, to automatically prove certain precisely specified properties, e.g. ``the airbag will always deploy within 20 milliseconds after a crash'' or ``the probability of both sensors failing simultaneously is less than 0.001''. The ability to formally guarantee quantitative properties of this kind is beneficial across a wide range of application domains. For example, in safety-critical systems, it may be essential to establish credible bounds on the probability with which certain failures or combinations of failures can occur. In embedded control systems, it is often important to comply with strict constraints on timing or resources. More generally, being able to derive guarantees on precisely specified levels of performance or efficiency is a valuable tool in the design of, for example, wireless networking protocols, robotic systems or power management algorithms, to name but a few. This report gives a short introduction to quantitative verification, focusing in particular on a widely used technique called model checking, and its generalisation to the analysis of quantitative aspects of a system such as timing, probabilistic behaviour or resource usage. The intended audience is industrial designers and developers of systems such as those highlighted above who could benefit from the application of quantitative verification,but lack expertise in formal verification or modelling

At Ease with Your Warnings: The Principles of the Salutogenesis Model Applied to Automatic Static Analysis

The results of an automatic static analysis run can be overwhelming, especially for beginners. The overflow of information and the resulting need for many decisions is mentally tiring and can cause stress symptoms. There are several models in health care which are designed to fight stress. One of these is the salutogenesis model created by Aaron Antonovsky. In this paper, we will present an idea on how to transfer this model into a triage and recommendation model for static analysis tools and give an example of how this can be implemented in FindBugs, a static analysis tool for Java.Comment: 5 pages, 4 figure

Moving outside the box: Researching e-learning in disruptive times

Indexación: Scopus.The rise of technology’s influence in a cross-section of fields within formal education, not to mention in the broader social world, has given rise to new forms in the way we view learning, i.e. what constitutes valid knowledge and how we arrive at that knowledge. Some scholars have claimed that technology is but a tool to support the meaning-making that lies at the root of knowledge production while others argue that technology is increasingly and inextricably intertwined not just with knowledge construction but with changes to knowledge makers themselves. Regardless which side one stands in this growing debate, it is difficult to deny that the processes we use to research learning supported by technology in order to understand these growing intricacies, have profound implications. In this paper, my aim is to argue and defend a call in the research on ICT for a critical reflective approach to researching technology use. Using examples from qualitative research in e-learning I have conducted on three continents over 15 years, and in diverse educational contexts, I seek to unravel the means and justification for research approaches that can lead to closing the gap between research and practice. These studies combined with those from a cross-disciplinary array of fields support the promotion of a research paradigm that examines the socio-cultural contexts of learning with ICT, at a time that coincides with technology becoming a social networking facilitator. Beyond the examples and justification of the merits and power of qualitative research to uncover the stories that matter in these socially embodied e-learning contexts, I discuss the methodologically and ethically charged decisions using emerging affordances of technology for analyzing and representing results, including visual ethnography. The implications both for the consumers and producers of research of moving outside the box of established research practices are yet unfathomable but excitinghttp://www.ejel.org/volume15/issue1/p5

T-infinity: The Dependency Inversion Principle for Rapid and Sustainable Multidisciplinary Software Development

The CFD Vision 2030 Study recommends that, NASA should develop and maintain an integrated simulation and software development infrastructure to enable rapid CFD technology maturation.... [S]oftware standards and interfaces must be emphasized and supported whenever possible, and open source models for noncritical technology components should be adopted. The current paper presents an approach to an open source development architecture, named T-infinity, for accelerated research in CFD leveraging the Dependency Inversion Principle to realize plugins that communicate through collections of functions without exposing internal data structures. Steady state flow visualization, mesh adaptation, fluid-structure interaction, and overset domain capabilities are demonstrated through compositions of plugins via standardized abstract interfaces without the need for source code dependencies between disciplines. Plugins interact through abstract interfaces thereby avoiding N 2 direct code-to-code data structure coupling where N is the number of codes. This plugin architecture enhances sustainable development by controlling the interaction between components to limit software complexity growth. The use of T-infinity abstract interfaces enables multidisciplinary application developers to leverage legacy applications alongside newly-developed capabilities. While rein, a description of interface details is deferred until the are more thoroughly tested and can be closed to modification

A Review of State-of-the-Art Large Sized Foam Cutting Rapid Prototyping and Manufacturing Technologies.

Purpose – Current additive rapid prototyping (RP) technologies fail to efficiently produce objects greater than 0.5?m3 due to restrictions in build size, build time and cost. A need exists to develop RP and manufacturing technologies capable of producing large objects in a rapid manner directly from computer-aided design data. Foam cutting RP is a relatively new technology capable of producing large complex objects using inexpensive materials. The purpose of this paper is to describe nine such technologies that have been developed or are currently being developed at institutions around the world. The relative merits of each system are discussed. Recommendations are given with the aim of enhancing the performance of existing and future foam cutting RP systems. Design/methodology/approach – The review is based on an extensive literature review covering academic publications, company documents and web site information. Findings – The paper provides insights into the different machine configurations and cutting strategies. The most successful machines and cutting strategies are identified. Research limitations/implications – Most of the foam cutting RP systems described have not been developed to the commercial level, thus a benchmark study directly comparing the nine systems was not possible. Originality/value – This paper provides the first overview of foam cutting RP technology, a field which is over a decade old. The information contained in this paper will help improve future developments in foam cutting RP systems