Checking Computations of Formal Method Tools - A Secondary Toolchain for ProB

We present the implementation of pyB, a predicate - and expression - checker for the B language. The tool is to be used for a secondary tool chain for data validation and data generation, with ProB being used in the primary tool chain. Indeed, pyB is an independent cleanroom-implementation which is used to double-check solutions generated by ProB, an animator and model-checker for B specifications. One of the major goals is to use ProB together with pyB to generate reliable outputs for high-integrity safety critical applications. Although pyB is still work in progress, the ProB/pyB toolchain has already been successfully tested on various industrial B machines and data validation tasks.Comment: In Proceedings F-IDE 2014, arXiv:1404.578

Using formal methods to support testing

Formal methods and testing are two important approaches that assist in the development of high quality software. While traditionally these approaches have been seen as rivals, in recent years a new consensus has developed in which they are seen as complementary. This article reviews the state of the art regarding ways in which the presence of a formal specification can be used to assist testing

Extraction of Insider Attack Scenarios from a Formal Information System Modeling

International audienceThe early detection of potential threats during the modelling phase of a Secure Information System is required because it favours the design of a robust access control policy and the prevention of malicious behaviours during the system execution. This paper deals with internal attacks which can be made by people inside the organization. Such at- tacks are difficult to find because insiders have authorized system access and also may be familiar with system policies and procedures. We are in- terested in finding attacks which conform to the access control policy, but lead to unwanted states. These attacks are favoured by policies involving authorization constraints, which grant or deny access depending on the evolution of the functional Information System state. In this context, we propose to model functional requirements and their Role Based Access Control (RBAC) policies using B machines and then to formally reason on both models. In order to extract insider attack scenarios from these B specifications our approach first investigates symbolic behaviours. The use of a model-checking tool allows to exhibit, from a symbolic behaviour, an observable concrete sequence of operations that can be followed by an attacker. In this paper, we show how this combination of symbolic execution and model-checking allows to find out such insider attack sce- narios

Leisure Is Hard Work: Digital Practices and Future Competencies

Part of the Volume on Youth, Identity, and Digital Media This chapter is based on two claims, namely that digital media are fundamental in nurturing human competencies for the future and that children's leisured media practices are critical catalysts in that process. These claims are documented by results from a recent case study on children's content creation of digital animation. Based on these results, the chapter discusses some of the fundamental challenges posed to educational institutions if they are to nurture future-directed competences for all pupils. These challenges include pupils' understanding of knowledge, their attitudes to learning resources and contexts of use, and the distribution of power relations. Like 300 million other kids around the globe, every Dane under the age of 20 knows that the protagonist of The Little Mermaid is Ariel, a fiesty redhead who manages to shape her fate and fortune. This fact is noteworthy only because Danish author Hans Christian Andersen, the author of the orignal fairy tale, composed a tragic tale of loss and redemption. The narrative and experiential discrepancies raise fundamental questions about the ways in which global and local media products frame children's everyday culture and the ways in which media operate as identity markers in a variety of sociocultural contexts. Moreover, Disney's figures, like many other media elements, are routinely appropriated by children in their own, increasingly digitized, media productions, from simple drawings to blogs, screen dumps, and home pages. These practices raise important issues about the role played by digital forms of media production for children vis a vis the more conventional and widespread forms of media reception

Animating the evolution of software

The use and development of open source software has increased significantly in the last decade. The high frequency of changes and releases across a distributed environment requires good project management tools in order to control the process adequately. However, even with these tools in place, the nature of the development and the fact that developers will often work on many other projects simultaneously, means that the developers are unlikely to have a clear picture of the current state of the project at any time. Furthermore, the poor documentation associated with many projects has a detrimental effect when encouraging new developers to contribute to the software. A typical version control repository contains a mine of information that is not always obvious and not easy to comprehend in its raw form. However, presenting this historical data in a suitable format by using software visualisation techniques allows the evolution of the software over a number of releases to be shown. This allows the changes that have been made to the software to be identified clearly, thus ensuring that the effect of those changes will also be emphasised. This then enables both managers and developers to gain a more detailed view of the current state of the project. The visualisation of evolving software introduces a number of new issues. This thesis investigates some of these issues in detail, and recommends a number of solutions in order to alleviate the problems that may otherwise arise. The solutions are then demonstrated in the definition of two new visualisations. These use historical data contained within version control repositories to show the evolution of the software at a number of levels of granularity. Additionally, animation is used as an integral part of both visualisations - not only to show the evolution by representing the progression of time, but also to highlight the changes that have occurred. Previously, the use of animation within software visualisation has been primarily restricted to small-scale, hand generated visualisations. However, this thesis shows the viability of using animation within software visualisation with automated visualisations on a large scale. In addition, evaluation of the visualisations has shown that they are suitable for showing the changes that have occurred in the software over a period of time, and subsequently how the software has evolved. These visualisations are therefore suitable for use by developers and managers involved with open source software. In addition, they also provide a basis for future research in evolutionary visualisations, software evolution and open source development

Making the Communication of CCS more "human"

CCS communication has proven a tough challenge, particularly for the difficulty in raising interest for the technology, which is still unknown to the majority of the population, and for the complexity of conveying information about its potential for reducing emissions. In this paper we present a research based effort for bringing CCS nearer to people, through visual material developed taking into account emotional needs related to the technology. The production of a short introductory film on CCS is illustrated and its testing with a sample of 700 high school students

Making sense of assets: Community asset mapping and related approaches for cultivating capacities

This working paper critically reviews some main aspects from asset based approaches highlights key strengths and weaknesses for future research/development. Drawing on a large body of reports and relevant literature we draw on different theoretical traditions and critiques, as well as practices and processes embedded within a broad range of approaches including, widely acknowledged frameworks such Asset Based Community Development (ABCD), Appreciative Inquiry (AI), Sustainable Livelihood Approaches (SLA) and Community Capitals Framework (CCF). Although these are presented as distinct approaches, there is a sense of evolution through them and many of them overlap (in terms of both theories and methodologies). We also include emerging frameworks, including geographical, socio-spatial, visual and creative approaches, stemming from a number of projects within AHRC’s Connected Communities programme and additional collaborations